The infrared emissivity characteristics and change mechanism of the superalloy K424 deposited with Ni/Au/Pt multilayer films were studied. After heat processing at 600 oC for 150 h, the films were analyzed by X-ray diffraction (XRD), SEM and EDS. The results show that the main compositions on the surface are Au0.7Cr0.3 and Pt, indicating that the substrate elements diffuse into the multilayer films. SEM analysis shows that there are lots of fine cracks on the rough sample, but oxides are not detected, while the surface of the polished samples is integrity after heat processing. The infrared emissivity was tested by spectral radiometer SR5000. The results show that both the surface state and heat processing have an important influence on the infrared emissivity