Sewage collecting device

The utility model relates to a sewage collecting device which comprises a shell, a placing disc used for placing a sampling cup is arranged on the upper surface of the shell, a first rotating shaft coaxial with the placing disc is rotatably connected to the upper end of the shell, and a shifting disc is arranged at the upper end of the first rotating shaft. The lower end of the first rotating shaft extends into the shell and is fixedly connected with a grooved wheel, a motor is arranged on one side of the first rotating shaft, a driving pin matched with the grooved wheel is eccentrically arranged at the output end of the motor, and a second rotating shaft is arranged between the inner top wall and the inner bottom wall of the shell. The first rotating shaft and the second rotating shaft are in transmission connection through a transmission mechanism, a winding disc used for winding a water pipe is arranged on the second rotating shaft, a water pump is arranged on the shell, one end of the water pipe is fixedl