A solar gas turbine power generation system based on a photothermal principle includes a gas turbine, a solar collector and a solar reflector, where the gas turbine includes a compressor impeller, a turbine, a recuperator and a combustion chamber, the recuperator includes an outer shell, an intermediate shell and an inner shell, a low-temperature gas inlet passage is formed between the intermediate shell and the outer shell, a high-temperature gas inlet passage is formed between the intermediate shell and the inner shell, an inlet and an outlet of the low-temperature gas inlet passage communicate with an outlet of the compressor impeller and an inlet of the combustion chamber, respectively, and an inlet and an outlet of the high-temperature gas inlet passage communicate with an outlet of the turbine and the outside, respectively; and the solar collector includes an absorber plate covering the outer shell of the recuperator.