This paper presents a model for extrapolating flux from cross-matching multiple catalogues combining the data of IRAS, WISE and 2MASS, which used the Planck’s law to extrapolate flux to every band. The model simplifies the extrapolation process, and improves the extrapolation efficiency with a high precision of 3% for 70% of the stars. Our finding is in agreement with the independent long-term observation of the Vega and Sirius star reported by Cohen et al. According to the extrapolation results, more suitable multiple data of stars could be selected for star calibration.