It is applicable to various large surface aquaculture. There are three kinds of crab nets: block net, pull net and silk net. 1. Blocking: It is a kind of fishing gear of river blocking type. When operating, the long net shall be folded longitudinally to the waist and laid to block the river. The river crab is blocked and caught in the net. Pay close attention to whether the net shakes in the water. If it shakes, pull the net gently at this time. When you see the crab, lift the upper and lower nets together and take the crab out of the net. 2. Towing net: It is a river blocking type ground pulling net fishing gear, in the shape of a strip. During operation, one end of the net shall be fixed on the bank, and then the river shall be blocked for distribution, and then the net shall be pulled around. 3. Wire mesh: single-layer gillnet fishing gear, in strip shape. During the operation, the net shall be placed to block the river, and the net shall be erected to form a wall at the bottom to cut off the river crab retreat and make the crab entangle in the net coat and catch it.