A combination of experiment and numerical simulation was used to study the response characteristics of laser-irradiated 45# steel plate. Based on the continuous fiber laser emission system, the laser irradiation experiment of the steel plate was carried out and the temperature field distribution and the ablation and perforation characteristics of the target plate were obtained. A finite element model of the metal target plate was established on the basis of ANSYS to simulate the thermal response process of the target plate under laser irradiation. The influence rules of the target plate thickness, laser power and spot diameter on temperature distribution and perforation characteristics of the target plate were obtained.