Sewage drainage mechanism of fishpond cleaning system

The invention discloses a sewage drainage mechanism of a fishpond cleaning system. The sewage drainage mechanism comprises a fishpond, a pond bottom of the fishpond is in a funnel shape, a sewage drainage port is formed in the pond bottom of the fishpond, a sewage drainage valve is installed on the sewage drainage port, and a driving mechanism is installed on the sewage drainage valve; the sewagedrainage valve comprises a valve body and a valve lid; the valve lid is rotatably fixed to the valve body; the valve body is further provided with a limiting block to control the maximal opening angleof the valve lid to be smaller than 90 degrees. According to the sewage drainage mechanism, the sewage drainage valve is arranged at the funnel-shaped pond bottom and communicated with the outside through a sewage drainage pipeline, so that the sewage drainage speed is high and the sewage drainage effect is good; besides, through the cooperation of an air cylinder/oil cylinder, a pulley and a traction rope, the valve lid of the sewage drainage valve is opened and closed conveniently; through limiting of a limiting plate, the opening angle of the valve lid is smaller than 90 degrees to avoid the situation that the opening angle is too large and a user cannot close the valve lid by himself/herself.