Miao Lei entered university of basel to study chemistry, and received his doctorate seven years later. Then, I work for Chigi Chemical Company. From 65438 to 0935, he began to study pesticides, during which his sister wrote from her hometown that there had been another pest disaster in her hometown, which accelerated his research. He recalled that when he was a child, an old man told him that China had a method of "fighting poison with poison". Inspired by this, he finally synthesized DDT in 1938 ~ 1939, but he didn't know the actual use. Then, he experimented with mice in the laboratory and found that DDT can cause itching, nausea and headache for several days. Later, experiments on mosquitoes, caterpillars and lice found that they would die immediately. He discovered the high-efficiency insecticidal power of DDT, making it the first organic synthetic insecticide widely used by human beings, and obtained a patent in 1942.