Affected by factors such as coating process,physical characteristics and aerodynamic stress,aircraft infrared stealth coating is prone to cracks,peeling and other damage.Monitoring the spectral emissivity is an effective means of monitoring the state of the infrared stealth coating.The calibration method of the spectral emissivity monitoring equipment directly affects the credibility of the coating emissivity measurement results,and then affects the evaluation results of the aircraft′s infrared stealth characteristics.Aiming at the calibration requirement of spectral emissivity measurement,the calibration method for the directional integral spectral reflectance measurement system is studied,and then the methods are applied to a certain coating sample measurement and calibration test.The result shows that the proposed calibration method can reduce the spectral emissivity error caused by the reference sample,and control the spectral emissivity error between the reference sample and the standard blackbody radiation source to be less than 0.02,and measurement indication error of the coating emissivity is also controlled within 0.03,which satisfies the measurement and calibration requirements of stealth coating monitoring.