The invention relates to a photovoltaic foundation steel pipe pile comprising a pile tip, a pile body, a pile top plate and an adjusting casing, wherein the lower end of the pile body is provided with the pile tip, the adjusting casing is sheathed and fixed on the top end of the pile body, and the top end of the pile body is welded with the pile top plate. The steel pipe pile provided by the invention has simple, compact and reasonable structure and beautiful appearance, the adjusting casing can be adjusted within a certain range according to the embedded height of the steel pipe pile, the flexibility is higher, and the applicable scope is wider. Compared with the similar power stations, the structure is used for reducing workload for digging and refilling the foundation so as to greatly reduce earth volume; under the condition of same investment, the difficulty that concrete can not be constructed in winter can be solved, the foundation construction speed is quickened, and the labor intensity of constructors can be lowered. In addition, the steel pipe pile provided by the invention can be effectively used for solving the construction problem for building large photovoltaic electric field foundation in the western desert area of China.