Thermal-mechanical impact failure problem of parabolic laser thrusters with air-breathing mode was studied experimentally and numerically. Four thermal loads i.e. the incident laser absorption, the radiation of high temperature gas, the transmitted laser absorption and the hot flow convection were proposed and the computational method of dynamic thermal-mechanical response of laser thruster was established. The calculated temperature rise of thrusters subjected to multiple laser pulses agreed well with the experimental measurement. The results show that for a parabolic thruster the thermal and mechanical damage mainly concentrates in the area near the apex and the mechanical fracturing will occur before melting. For a self-focus parabolic thruster the main temperature increase factors are the incident laser absorption and the high temperature gas radiation, while for an outside focus thruster, the main factor is the transmitted laser absorption near the apex. Thermal protection is needed for future laser thruster design.