The present invention designs a measurement scheme for the longitudinal temperature of the film during nitride epitaxial growth, belongs to the field of semiconductor measurement technology. Epitaxial growth technology is one of the most effective methods for preparing nitride materials. The temperature during the growth process restricts the performance of the device. The non-contact temperature measurement method is generally used to measure the temperature of the graphite disk as the base, which can't obtain the longitudinal temperature. The present invention respectively measures the surface temperature of the epitaxial layer and the temperature of the graphite disk by ultraviolet and infrared radiation temperature measurement technologies, and then uses the finite element simulation method to perform thermal field analysis from the bottom surface of the substrate to the surface of the epitaxial layer, so that the longitudinal temperature is obtained, thereby providing a favorable basis for temperature regulation during nitride growth.