A sea creature cleaning robot for an intake tunnel for a nuclear power plant includes a frame, cutter assemblies, and walking wheel assemblies; the frame is used for mounting and fixing cutter mounting seats and crawler wheels; the walking wheel assemblies mounted on the frame enable the entire device to normally walk in a tunnel; the cutter assemblies control the height of cutters by means of hydraulic cylinders to make the cutters contact the inner wall of the tunnel, and the hydraulic cylinders drive the saw-toothed cutters to move back and forth to remove sea creatures attached to the inner wall of the tunnel; the cutter assemblies are uniformly distributed on the frame, so as to ensure full coverage of the cleaning range of the cross section of the tunnel. The robot can clean sea creatures in tunnels in place of manual work to significantly improve the cleaning efficiency.