The invention discloses a zinc powder sherardizing method enabling the thickness of a zinc coat to be considerable and uniform. The method comprises the steps of sand blasting, encasing, powder blending, zinc sherardizing, centrifugal zinc shredding, cooling, selecting and packaging. A zinc powder sherardizing agent used during zinc sherardizing comprises the following raw materials of zinc powder, zeolite powder, aluminum chloride powder, aluminum oxide powder, aluminum sulfate powder, cobaltous oxide powder, lead powder, magnesium stearate powder, sodium borate powder, calcium silicate powder, graphene powder, a surfactant, a dispersing agent, a modifier, an activating agent, a diffusant, an intensifier, a chelating agent, an sherardizing accelerant and a stabilizer. The zinc coat of a zinc powder sherardizing product prepared through the method is considerable and uniform in thickness and free of hydrogen embrittlement or surface damage, the zinc sherardizing technology process is free of environment pollution, the zinc utilization rate is high, and the raw materials can be effectively saved.