Protection device capable of preventing high-liquid-level overflow and low-liquid-level water shortage of membrane pool

The utility model provides a protection device capable of preventing high-liquid-level overflow and low-liquid-level water shortage of a membrane pool. The liquid level of the membrane pool is detected through a high probe and a low probe; double guarantees are formed with the existing liquid level sensor of the membrane pool; even if liquid level sensor fails, whether liquid in the membrane poolis at a high liquid level or not can be detected in time through the protection device, overflow is prevented by forcibly closing the water inlet pump, meanwhile, whether liquid in the membrane pool is at a low liquid level or not can be detected, water shortage at the low liquid level is prevented by forcibly closing the water outlet pump, and then the membrane pool is protected and the liquid level in the membrane pool is in a normal state. Besides, the utility model further designs a sliding device capable of sliding along the length direction of the membrane pool; the sliding device can carry the controller to mov