In the early days of the People's Republic of China, the strength of chemical research was very weak. During the period of 1949, there was only one Beijing Chemical Comprehensive Laboratory and one Zhejiang Chemical Research Institute, and the number of scientific researchers was very small. In July 1953, the state moved the above two chemical research institutions to Shenyang, and merged them with the research office set up by the Chemical Industry Bureau of the Northeast Ministry of Industry to form the Shenyang Chemical Comprehensive Experimental Research Institute. Combined with the needs of production development, the institute has accelerated the development of scientific and technological strength and equipment. By the end of 1955, the institute had more than 2,000 employees, including more than 400 scientific and technical personnel. Its research field has expanded from dyes and their intermediates to mineral processing, phosphate fertilizer, potash fertilizer, inorganic salts, organic synthesis, synthetic resin, pesticides, coatings and other specialties, and it has become the most comprehensive research institution in China's chemical industry system. 1956 After the establishment of the Ministry of Chemical Industry, Li Su successively served as assistant minister and deputy minister, and was in charge of the leadership of chemical science and technology organizations for a long time. He attaches great importance to the construction of chemical research institutions, gathers scientific and technological talents, expands scientific research teams, organizes scientific research projects in key fields, conducts applied basic theoretical research in combination with production development, and promotes technological progress of enterprises. In order to fully implement 1956- 1967 "Twelve-year Science and Technology Development Vision Plan" and establish a complete chemical research system, Li Su was ordered to organize investigation and study, put forward the establishment plan and be responsible for organizing its implementation. The laboratories of organic synthesis and synthetic resin in Shenyang Institute of Chemical Engineering have been moved to Beijing one after another, and Beijing Institute of Chemical Technology has been established to engage in scientific research tasks in the field of petrochemical industry. The inorganic salt and coating laboratory was moved to Tianjin, and Tianjin Institute of Chemical Industry was established to engage in scientific research tasks such as mineral processing, pigments and coatings. The chemical mineral processing and fertilizer laboratory was moved to Shanghai, and Shanghai Institute of Chemical Technology was established to undertake the scientific research tasks of mineral processing and NPK fertilizer. The remaining dye and pesticide laboratory was reorganized into Shenyang Institute of Chemical Industry. With the development of chemical production and construction, after 1958, Tianjin Rubber Industry Research Institute and Beijing Rubber Industry Design Institute merged to form Beijing Rubber Industry Research and Design Institute, and at the same time, the pharmaceutical industry research institute was established in Beijing, and the Shanghai Pharmaceutical Industry Research Institute was reorganized into Shanghai Pharmaceutical Industry Research Institute. In the early 1960s, he presided over the establishment of several professional research institutes in chemical machinery, synthetic fiber and carbon black industry. Organize several large chemical bases in Lanzhou, Jilin, Nanjing, Jinxi and Sichuan to set up chemical professional research institutes (institutes) respectively. In the construction of these scientific research institutions, Li Su has done a great deal of organization, management and coordination from planning to organization planning, from the choice of institution address to the implementation of capital construction, from the arrangement of leading institutions to the allocation of scientific research forces, from the setting of specialties to the purchase of instruments and equipment. He also went deep into the grassroots to solve problems in the construction of research institutes and the working and living conditions of researchers. After 10 years of efforts, a complete scientific research system and a strong scientific research team for chemical engineering specialty have finally been gradually formed. According to the statistics of 1966, there are 27 scientific research institutes directly under the Ministry of Chemical Industry, with more than 4,000 employees and more than 4,000 researchers, which are 7 times and 0/0 times of 1955 respectively.
During this period, the vast number of scientific and technological personnel in the chemical research front carried forward the spirit of self-reliance and hard struggle, overcame many difficulties, participated in major scientific research projects, and achieved a large number of scientific research results, such as the successful development of new technologies, new processes, new equipment and new products such as dihydrate wet-process phosphoric acid, catalyst for purifying synthetic gas, organophosphorus pesticides, PVC, PTFE plastics, synthetic rubber, dyes, medicines, rubber products and chemical reagents. In the process of organizing tough battles, Li Su always adhered to the principle of "great cooperation", United all technical forces and cooperated closely, which made contributions to the full realization of China's 12 science and technology development plan and the promotion of chemical science and technology progress.
1972, the Ministry of Fuel Chemical Industry decided to establish a petrochemical research institute, which is in charge of petroleum refining and chemical research, with Li Su as its president. During the six years from 65438 to 0978, the Institute organized a campaign to tackle key scientific and technological problems in the petrochemical industry, achieved many achievements, digested and absorbed many imported technologies, and promoted the development of the petrochemical industry.