NOVELTY - The device comprises a water inlet A, and a water inlet B. A liquid water tank is connected to a liquid peristaltic pump and a sequencing batch bioreactor through the water inlet A and the water inlet B. The sequencing batch bioreactor is equipped with a cantilever type stirrer connected with a nitrogen open type electromagnetic valve to control diffusion of a sand core aeration head, a dissolved oxygen line sensor, pH line sensor, and a temperature line sensor. The temperature line sensor is connected to a heating device.    USE - The device is useful for testing concentration of phosphorus accumulating bacteria in sludge (claimed).    ADVANTAGE - The device is capable of testing the concentration of phosphorus accumulating bacteria in sludge to 80% by controlling pH value and temperature of the reaction and dissolved oxygen content.    DETAILED DESCRIPTION - The device comprises a water inlet A, and a water inlet B. A liquid water tank is connected to a liquid peristaltic pump and a sequencing batch bioreactor through the water inlet A and the water inlet B. The sequencing batch bioreactor is equipped with a cantilever type stirrer connected with a nitrogen open type electromagnetic valve to control diffusion of a sand core aeration head, a dissolved oxygen line sensor, pH line sensor, and a temperature line sensor. The temperature line sensor is connected to a heating device. The sequencing batch bioreactor is connected to an acid-alkali peristaltic pump, a sludge discharging peristaltic pump, a drainage electric valve, and multi-parameter measuring instrument through a simulator. The simulator is connected to a programmable logic controller, which is connected to a centralized control system. The centralized control system includes a data acquisition device, a signal converter, a variable controller, a water anaerobic/aerobic sequencing batch biological test equipment, a separate precipitator, a supernatant discharge outlet, and an idle stage unit. The opening and closing time of the water inlet A and the water inlet B of the liquid peristaltic pump, the cantilever type stirrer, nitrogen open type electromagnetic valve, the sludge discharging peristaltic pump and the drainage electric valve are controlled through an input alternating current of the centralized control system. The reaction process in the device is monitored using the pH line sensor and the temperature line sensor. The data acquisition device is connected to the multi-parameter online measuring instrument, which is further connected to the simulator to simulate signal. The signal converter converts the signal and then transmits to the programmable logic controller. The programmable logic controller transmits the signal to the centralized control system. The centralized control system determines the opening or closing of the heating device, the liquid peristaltic pump and the acid-alkali peristaltic pump. The dissolved oxygen line sensor collects the dissolved oxygen value through the multi-parameter measuring instrument. The centralized control system controls a dissolved oxygen electromagnetic valve.