In order to evaluate the influence of cold surface adiabatic boundary, after fully verifying the controllability and the stability of the heat radiation testing system, flexible insulation mat, rigid insulation tile and nano insulation material were used as cold surface insulation boundary respectively. The thermal radiation test of quartz lamp at 500℃ and 3 000 s was carried out, and the test results were simulated and analyzed by using iterative equivalent method. The results show that the cold surface temperature of ceramic fiber rigid insulation material is the highest when flexible insulation mat is used , while the cold surface temperature is lower and similar when rigid insulation tile and nano insulation material are used as the boundary, with maximum relative deviation of 19.0 % between the highest and lowest. Simulation results show that the contact thermal resistance caused by the cold surface insulating boundary material plays a decisive role in tests, rather than simply depending on the insulation performance of the insulating material.