The steps of switching two chlorine compressors in Befar Group Co., Ltd. are introduced. In the process of switching, the chlorine pressure is easy to fluctuate at the startup of the chlorine compressor;the operation of too many valves is easy to cause the fluctuation of chlorine pressure;the inlet pressure of the two compressors is different after the opening of the inlet valve;the load does not increase after the anti-surge backflow is limited;after the switching is completed, the inlet valve is not tightly closed. The causes of various problems are analyzed, and the corresponding solutions are given. The switching operation experience is also introduced. Through improvement, the stable switching of the compressors is realized, so that the standby compressor can be effectively used as standby. At the same time, according to the change in production load and the need of chlorine downstream, appropriate compressor can be used to improve the operational flexibility of the device.