In order to improve the efficiency of laser surgery and reduce the damage to surrounding healthy tissues during laser surgery, the influence of the peak power of pulsed holmium laser and continuous thulium laser power on the thermal effect of soft tissues was explored. Build an in vitro model device to find the optimal parameters for laser ablation of tissue, the pulsed holmium laser power is 20W, 40W, 60W, 80W, the pulse duration is 200μs and 800μs, and the pulse energy is 1J, 2J, 4J. The continuous thulium laser power is 20W, 40W, 60W, 80W, 100W, 110W. Finally, the in vitro model was placed in physiological saline and kept at a constant room temperature for experiments. The damaged tissue after laser ablation was sliced and stained, and pathological slices were analyzed. The peak pulse power has a great influence on the ablation zone of soft tissue. The ablation depth of the laser combination with the pulse energy of 4J×10Hz is 111.82% higher than that of the laser combination with the pulse energy of 1J×40Hz, while the effect on the solidification zone is only 9.96%. Pulse duration had little effect on soft tissue, and ablation depth was increased by 18.49% with shorter pulse width. The ablation depth of tissue increases with the increase of the power of continuous thulium laser, and the ablation efficiency is correspondingly increased, and the hot solidification zone is almost unaffected. The ablation efficiency of 100W is nearly 88.26% higher than that of 20W.