As the current channel-type liquid cooling plate generally suffer from high pressure loss and low cooling efficiency, making electric vehicles have to face problems such as high battery pack temperature and short mileage. To solve the above problems with channelized liquid-cooled plate, the conventional liquid-cooled channel was first rectangularly finned, and the size of the fins was optimized by varying the longitudinal spacing ratio f/a and transverse spacing ratio w/b between adjacent fins. Results show that the liquid-cooled plate had the lowest average temperature and pressure drop and the best overall performance when the size of the fins in the corresponding directions and the size of the spacing between the corresponding directions were equal. Secondly, on the basis of the optimization, the preferred fin form was preliminarily biomimetic. CFD simulation results show that the bionic limulus-like fins (BLLF) were more effective, with pressure drop (ΔP) and average temperature (T_ave) improved to a certain extent, compared with the rectangular and oval conventional shape fins. Subsequently, the number of inlets and outlets and their layout positions were discussed. Then, in order to further improve the performance of the cold plate, according to the shape characteristics of the limulus, the scrambler fins were homogenized to form a central channel and two secondary channels were added diagonally upward, which continued to construct a new type of microfin for the bionic limulus, and a multi-objective optimization of the secondary channels was carried out with L, W, α, and β as the parameters. Compared with the original model, T_ave and ΔP of the optimal model were reduced by 1.69 °C (4.61 %) and 6.81 Pa (54.26 %). Finally, the effect of the variation of Reynolds number on the thermal performance was discussed. It can be seen that the bionic fin design approach obtained in this study will provide a reference for liquid-cooled channel finning optimization.