Is it legal to reduce salary because of poor management of the company?

Legal analysis: illegal. Lowering salary and demotion belongs to changing labor relations without authorization. You can refuse, apply for labor arbitration, demand payment of economic compensation and double wages, and do not sign a written labor contract. The employing unit shall not delay the deduction of workers' wages for any reason, even if it is poorly managed. In practice, the company can only reduce employees' wages under the following circumstances. Employees violate company discipline and are incompetent.

Legal basis: Article 38 of People's Republic of China (PRC) Labor Contract Law. Under any of the following circumstances, the laborer may terminate the labor contract: (1) failing to provide labor protection or working conditions as agreed in the labor contract; (2) Failing to pay labor remuneration in full and on time; (3) Failing to pay social insurance premiums for laborers according to law; (4) The rules and regulations of the employing unit violate the provisions of laws and regulations and damage the rights and interests of workers; (5) The labor contract is invalid due to the circumstances specified in the first paragraph of Article 26 of this Law; (6) Other circumstances under which the laborer can terminate the labor contract as stipulated by laws and administrative regulations. If the employer forces the laborer to work by means of violence, threat or illegal restriction of personal freedom, or if the employer illegally directs or forces the risky operation to endanger the personal safety of the laborer, the laborer may immediately terminate the labor contract without notifying the employer in advance.