In this study, to improve the microstructure of the cladding layer and strengthen the surface properties of 42CrMo, the mechanism of the influence of temperature on the microstructure and microhardness of the cladding layer under different cladding powers were investigated using numerical simulation and cladding tests based on the multipass cladding of H13-TiC composite powder on 42CrMo substrate. In addition, based on the temperature variability of material properties, a laser cladding model is established, and the mechanism of the influence of power on the surface temperature and residual stress fields of the cladding layer is analyzed. Furthermore, the microstructure and element distribution of the H13-TiC composite cladding layer were analyzed by scanning electron microscope, and the relationship between the morphology distribution of TiC particles and microhardness was studied. The results show that when the laser power increases from 2000 W to 2850 W, the peak temperature of the third track increases by 34.4% and reaches 3471.53 ℃ at 2850 W. The residual stress on the track surface reveals the distribution law of large in the middle and small at both ends. The number of TiC fine particles in the cladding layer gradually increases with an increase in temperature. When the power was 2850 W, the TiC fine particles were uniformly dispersed, increasing microhardness of 33%?50% outside the TiC aggregation area. Here, the microstructure and microhardness of the cladding layer are improved by analyzing the variation law of the temperature and residual stress fields between tracks during power increase, thereby providing a theoretical basis for the application of laser cladding technology in pick material 42CrMo.