Sewage tank

The utility model discloses a sewage tank which comprises a tank body, a separation device and a water inlet piece, the tank body comprises a water storage part and an installation part, and a water return part extending into a water storage cavity is formed in the installation cavity; the separation device is rotatably connected in the mounting cavity and is used for carrying out gas-liquid separation on the sucked fluid; the separation device comprises an air outlet pipeline and a lower conveying channel, the water inlet piece penetrates through the water return part, and the water inlet piece is configured to be used for conveying sucked fluid into the separation device; a water return channel is formed between the water return part and the water inlet piece, a one-way valve set is formed in the water return channel and is configured to be used for achieving one-way conveying of fluid from the lower conveying channel to the water storage cavity, it is advantageously avoided that sewage in the water storage