Nano-silicon slurry with heavily doped boron is used as the source of boron, and nanosecond laser cladding process is used to form a heavily doped boron silicon cladding layer on the back of passivated emitter rear contact (PERC) solar cells. The finite element simulation model of three-dimensional transient temperature field is established. Based on this model and single factor simulation experiments, the influence rules of laser process parameters on temperature field are obtained and reasonable range of laser process parameters is preliminarily determined. Through range analysis, the interaction law between laser processing parameters and temperature field distribution of laser cladding is obtained. Laser cladding process is compatible with PERC solar cells preparation experiment. The experimental results show that the simulation model is consistent with the experimental results, and the average photoelectric conversion efficiency of the solar cell is improved by 0.27%.