To predict the failure time of carbon fiber/ epoxy resin reinforced composite laminates under the combined action of laser and mechanical load, different laser power density (70–210 W/cm²), different pre-stress levels (50% and 70% of tensile strength) were studied experimentally. The failure mechanism of 2 mm laminates under different spot sizes (70% and 100% of the width of tensile specimens) was obtained, and the influence rule of different influencing factors on fracture time was obtained. The results show that the failure mechanism of pre-loaded laminates is the pyrolysis of the substrate material of epoxy resin, the oxidation fracture of the fiber and the brittle fracture of the residual structure of the back surface. Under certain pre-stress conditions, the fracture time and the irradiated laser power density are exponential. The pre-stress level has a significant effect on the fracture time.