Abstract: In view of the problem of sticking in the vacuum pump of gypsum dehydrator in a power plant in Jiangsu province, the chemical composition of the bearing surface scaling is analyzed, and the reason for the scaling jam is analyzed. After the working medium water in the pump changed from industrial water to the wastewater treated from chemical water, the pH is high, the calcium and magnesium hardness is large, and it is easy to scale. After taking the measures of chemical cleaning, the vacuum pump can be restored to normal operation in a short period of time. At the same time, The paper puts forward a series of improvement measures for the operation of a series of equipment such as regular inspection of the reuse water system and installating the pH meter in the jellyfish tube of the return water of the third-stage industrial wastewater at the effluent side of the reuse pool, which effectively solve the problem of scaling and jamming of the vacuum pump.