An electrolyte for surface treatment of a metal implant includes 10-30 wt % of a sulfur-containing compound aqueous solution, 3-10 wt % of a phosphorous-containing compound aqueous solution, 0.5-2 wt % of an oxidant aqueous solution, and 0.5-5 wt % of a surfactant aqueous solution, with the rest being water. The concentration of the sulfur-containing compound aqueous solution is 0.1-3 M. The concentration of the phosphorous-containing compound aqueous solution is 0.05-2 M. The concentration of the oxidant aqueous solution is 0.05-1 M. The concentration of the surfactant aqueous solution is 0.05-5 M. The electrolyte is utilized for treating a surface of a metal implant, forming a porous oxide layer on the surface of the metal implant.