The causes and hazards of chlorate formation in ion exchange membrane caustic soda systems are introduced.Two common methods for removing chlorates,discharge method and chemical removal method,are described.Chlorate decomposition by ZYUC-13 reagent is tested.The mass concentration of chlorate after decomposition is basically stable at around 1 mg/L,and the decomposition effect is significant.However,the reagent corrodes the equipment severely during test,and the gases produced by side reactions pose significant safety hazards to the production system.