An automatic multi-point water quality monitoring system integrated with a sensor cleaning device was designed to solve the problem of the high cost of on-line monitoring of water quality sensors in aquaculture and the influence of surface algae and fouling on sensor detection accuracy. In considering of the gradual change of water quality parameters in aquaculture, a kind of multi-sink water quality sampling tank including clean water tanks was designed by adopting a sensor time-sharing multiplexing scheme, with which the water samples needing to be monitored online are transferred to the corresponding sampling tanks; the multi-point water quality cycle monitoring is realized by switching sensor modules controlled by a three-axis moving platform; and the sensor can be cleaned and maintained through the cleaning brush set in the cleaning water tank. PLC is preferred as the main controller to control the actuators, solenoid valves, water pumps, three-axis moving platforms and other executable devices. The on-site human-computer interaction is realized through the MCGS touch screen, the data exchange between which and the PLC is realized through the RS232 bus so as to realize the equipment status monitoring and the real-time display, storage and historical information statistics of test data. The results showed that the system was stable and reliable, the operation interface was normal, and the system can effectively improve the adhesion of algae and microorganisms on the sensor through the combination of clean water immersion, water flow rinsing and flexible wiping with sponges.