UV luminescence spectra of high purity MgO crystals and Sc doped MgO crystals were tested by self-built experiment platform.The crystals were expose d to vacuum ultraviolet radiation first,and then the emission spectra were tested under different annealing temperatures.The emission peaks are located at 389.31nm,498.61nm, 712.44nm and 749.06nm respectively,which have great accordance wit h the calculation results got by first-principles.The visible emission region and infrared emis sion region are attributed to F and F+ color centers constituted by oxygen vacancy lo cated in MgO crystal.The excitation and relaxation mechanisms caused by electrons emit ted from color center and trapped by color center play an important role for these emission regions.Furthermore,we tested photoluminescence spectra of Sc doped crystals under different annealing temperatures,and F color center and F⁺ colo r center of crystals are located by Gauss decomposition.The results show that high tempera ture annealing treatment not only reduces the MgO crystal surface contamination but a lso increases the optical activity of crystal.Meanwhile,Sc doping leads to the enhan cement and blue shift of visible light emission region in crystal,while F ⁺ color center has more strong temperature dependence.