According to the characteristics of the Mopiling nature-like fishway project and the requirements of fish passing，a three-dimensional turbulent numerical model of fishway pools is established，and the scale of the fishway bottom slope and rest pools is demonstrated. The results show that：1）The vertical slot layout of the fishway can meet the demand of fish upstream. When the bottom slope is 1/250，the maximum velocity of the vertical slot and the bottom hole is 0.90 m/s.2）There is a large range of small flow velocity area in rest pools of different schemes，which can be used for fish upstream rest.3）The range of small velocity areas in rest pools of 20 m pool length scheme is larger than that of 10 m pool length scheme. In addition，it can better meet the needs of fish.