When the content of combustible gas or combustible dust in the air reaches the explosion limit, it will burn violently when it meets an open flame, which will cause the gas to expand rapidly in a limited space, thus causing an explosion. The severity of explosive chemical reaction is related to whether the concentration of combustible substances reaches the explosion limit. In order to avoid explosion accidents, the safety measures that the flour mill should take are to eliminate all factors that may cause sparks, cut off the power supply, check frequently, and reduce dust and air intake.