Abstract: In the method of active electromagnetic excitation infrared nondestructive detection, the selection of electromagnetic excitation parameter is one of the important factors that determine nondestructive testing effect. Firstly, the relation between electromagnetic excitation parameters (excitation power, coil length, coil equivalent diameter, lift-off distance, excitation time, etc) and excitation thermal effect was analyzed through orthogonal test. The mathematical model between parameters and excitation thermal effect was built based on the partial least-squares regression. Lastly, the model was verified by 15 experiment samples. The result shows that the average error of mathematical model is 9.79%; lift-off distance affects most among the excitation parameters, followed by coil length, coil equivalent diameter, excitation time and excitation power.