Atmospheric heat source is one of the main points of the theory of plateau meteorology. The studies on its calculation method and applicability are of great significance to deepen the understanding of plateau meteorology and broaden the horizon of students of this course. The precise calculation of atmospheric heat source remains a challenge. We introduced two methods for calculating the atmospheric heat sources in detail. Based on historical observations of meterological stations, satellite-based radiation datasets (ISCCP and SRB) and four reanalysis datasets (NCEP/NCAR, NCEP/DOE, ERA-Interim and JRA55), we calculated the atmospheric heat sources in summer season over the Tibetan Plateau and compared their differences in multiscale vaiabilities. The results showed that radiation data should be carefully selected in calculating the atmospheric column energy budget. When the atmospheric apparent heat sources are calculated, the reanalysis date should be carefully selected according to the focus of the timescale owing to their quite different performances. In terms of the long-term trend, <Q1>-JRA55 is the closest to observations; on the interannual time scale, the results of <Q1>-ERAI and <Q1>-JRA55 can repeat the variability of the heat source from observations; and on the intraseasonal oscillation, the differences of multiple sets of reanalysis data have been narrowed, and they all can be used well to describe the changes of the heat source over the Tibetan Plateau.