The invention relates to a method for depositing bionic hydroxyapatite (HA) on a zinc phosphate conversion coating surface, which comprises the following steps: preparing a simulated body fluid, in which the solute concentrations are as follows: 8.035-16.07g / L sodium chloride, 0.355-0.71g / L sodium bicarbonate, 0.225-0.45g / L potassium chloride, 0.231-0.462g / L dipotassium hydrogen phosphate dihydrate, 0.311-0.622g / L magnesium chloride hexahydrate, 39-58.5mL / L 1mol / L hydrochloric acid, 0.292-0.584g / L calcium chloride and 0.072-0.144g / L sodium sulfate; and cleaning a stainless steel sample of which the surface is provided with the zinc phosphate chemical conversion coating, putting the cleaned sample into the simulated body fluid, putting in a 36-38 DEG C thermostatic water bath oscillator, immersing for 0.5-30 days, taking out, cleaning with deionized water, and drying to obtain the HA coating. The composite coating is beneficial to enhancing the corrosion resistance of the stainless steel implant, has excellent biological activity, and implements early healing and long-term stability of the stainless steel implant.