Graded purification earth pond for river crab culture tail water

The utility model relates to the field of river crab breeding, and discloses a river crab breeding tail water grading purification earth pond which comprises a shell, a water inlet hole is formed in the top of the shell, a sliding groove is formed in the inner side wall of the shell, a frame is movably connected to the inner wall of the shell, a sliding block is arranged on the outer wall of the frame, and the sliding block is movably connected with the shell. A containing box is fixedly connected to the bottom of the frame, a baffle is fixedly connected to one side of the frame, a handle is fixedly connected to one side of the baffle, a flow baffle is fixedly connected to the bottom of the shell, a mounting base is fixedly connected to the top of the shell, and a pin shaft is arranged on the front face of the mounting base. According to the river crab breeding tail water grading purification earth pond, people can replace used soil more conveniently when using the purification earth pond, compared with a com