At present, about 80 percent of rough sapphire mined from the Mogok mine in Myanmar must be optimized before being put into the market, mainly heat treatment. In this paper, the sapphire from Baw-mar mine, Mogok, Myanmar is heat treated with different temperature regimes, and X-ray fluorescence spectrometer (XRF), X-ray powder crystal diffractometer (XRD), Ultraviolet-visible-near infrared spectrometer (UV-Vis-NIR), Fourier infrared spectrometer (FTIR) and Laser Raman spectrometer (Raman) were used to compare the spectroscopic characteristics before and after heat treatment. The results show that all sapphire XRD peaks with 2θ < 60° start to shift to low-angle after heat treatment at 1300℃, and the unit cell parameter c/a ratio decreases with the increase of heat treatment temperature, indicating that the crystal structure is distorted at high temperatures. The main color-causing elements of sapphire from Baw-mar mine are Fe, Ti, and V. Ni is the cause of the gray tone. After the heat treatment, the Fe2+-Ti4+ ion pair transfer is enhanced, and the Fe2+-Fe3+ ion pair transfer is weakened, resulting in an enhanced 585nm ultraviolet absorption band and a weakened absorption peak at 746 and 764nm. At the same time, the color of the sample turns blue and the gray tone weakens. In the infrared spectra, the sapphire from this mine has 1988, 2123cm-1 diaspore hydroxyl frequency doubled vibration absorption peaks and 3619, 3696cm-1 kaolinite outer hydroxyl and inner hydroxyl vibration absorption peaks. After the heat treatment, the diaspore and kaolinite are completely dehydrated, and the crystal structure is destroyed, resulting in the disappearance of all the hydroxyl absorption peaks. After heat treatment at 1100℃, the Raman peak at 1324cm-1 appeared and gradually increased with the increase of temperature. It is speculated that it is caused by the reaction of molten borax and Al2O3 at high temperature to form glassy substances along the cracks and enter the interior of the sapphire. This article provides reliable identification data for non-destructive testing of sapphire from this mine through spectroscopic feature analysis, and also provides ideas and theoretical basis for further discussion of its color modification process.