The invention discloses an output water pressurizing device of an overflowing 
settling tank, which is designed to pressurize output water from an overflowing 
settling tank. The output water pressurizing device of the overflowing 
settling tank is characterized in that the overflowing settling tank is connected with the upper part of a closed water tank through a high-level water tank; the top of the closed water tank is connected with a combined air vent valve and a 
water pressure sensor; the lower part of the closed water tank is connected with a water pump water suction 
pipe; the bottom of the closed water tank is connected with an emptying valve; a water output end of the water pump water suction 
pipe is connected and communicated with a water pump of a control cabinet, a 
check valve, an electric flow adjustment valve and a de-oiling tank. The pressurizing device is capable of automatically turning on and off the water pump according to pressure variation of the close water tank, and continuously adjusting the opening degree of the electric flow adjustment valve, so that the flow of output water of the overflowing settling tank and the flow of the water pump can be consistent, and the 
system can run continuously and safely; a water inlet 
pipe of the water tank and the water pump water suction pipe are arranged inside the closed water tank in an upper input and lower output manner, so that air in output water of the high-level water tank can be sufficiently separated out inside the tank and removed. Therefore, the 
cavitation phenomenon can be avoided. The pressurizing device uses an airtight method to pressurize the overflowing settling tank to output water, and has the advantages of good 
water supply continuity and 
high security property.