Abstract: There exists evident surface recombination of atoms in the high enthalpy aero-heating test. When the catalysis of TPM (Thermal Protection Material) is low, the calibration of aero-heating should consider surface recombination; otherwise it would cause under-estimation of TPM. Based on the flat aero-heating test, the analysis method of surface recombination effects in the arc-jet flow was developed by comparison of the structure heat transfer simulation and test data. This method can evaluate surface recombination effects on special TPM in arc-jet tests, and give support on modification and improvement of test projects. The analysis results show that, for a kind of TPM, the surface recombination effect makes the real aero-heating to be only about 85 percent of the calibrated heat flux. Therefore, the surface recombination effect should be considered when the copper sensor is used to calibrate the aero-heating, and the flow condition should be enhanced to ensure effective assessment.