Recent studies show that surface texture with reasonable parameters can improve tribological properties of materials and prolong the service life of machinery. Laser ablation of dimples on the surface of Ni60/WC coating of fracturing pump plunger is an effective means to improve the lubrication and wear resistance of the plunger-root seal system. However, the accumulation at the bottom of the dimples produced by the current grid filling method is serious, which is not conducive to the improvement of wear resistance of the plunger coating by dimples. In order to optimize the filling methods of laser path and reduce the accumulation at the bottom of dimples in picosecond machining, the effect of key picosecond laser parameters on the surface of Ni60/WC coatings under this path on the shape parameters of dimples was investigated. A dimple with a diameter of 230 μm was planned on the surface of the Ni60/WC coating through the built picosecond processing platform and the ultraviolet picosecond laser micro-processing platform. The bottom morphology of the dimple was characterized by the 3D morphology obtained by white-light interferometer test. The concentric grid composite filling method was used to optimize the stacking phenomenon at the bottom of dimples, and the single factor method was used to analyze the effect of picosecond laser processing power, scanning times and scanning speed on the depth, diameter and roundness coefficient of dimples. The results showed that the removal volume of dimple materials obtained by the optimized concentric circle grid filling method was 7.59×106 μm3, and the arithmetic average height of contour was 1.37 μm, which showed no obvious accumulation compared with the original grid filling method. Based on the filling path, the depth, diameter and roundness coefficient of the dimples increased as a quadratic function with the increase of laser power within the testing parameters. With the increase of the scanning speed, the depth and diameter of dimples decreased linearly, while the roundness coefficient increased linearly. The depth, diameter and roundness coefficient of dimples increased linearly with the increase of scanning times. In conclusion, the concentric circle mesh composite filling method can effectively improve the accumulation phenomenon at the bottom of dimples during picosecond machining of Ni60/WC coating surface. For the dimples with diameter of (230±5) μm and depth of (30±5) μm, the optimal range of picosecond laser processing parameters is as follows:the laser power is 6-7 W, the scanning speed is 6 000-8 000 mm/s, and the scanning times are 1-2 times. This study optimizes the picosecond laser bottom stacking of Ni60/WC coating material with dimple texture parameters arranged on the surface, and optimizes the laser processing range. In this study, the key parameter evaluation method of picosecond laser processing for designing texture parameters of dimples on the surface of Ni60/WC coating material is preliminarily formed, which lays a foundation for industrial processing of optimum texture on Ni60/WC coating surface by laser beam splitting technology.