The invention discloses a method for preparing a two-stage micron-submicron microstructure on the surface of a titanium alloy dental implant. The titanium alloy implant is activated, and is processed through surface modification such as direct current electrolytic etching and alternating current etching, so that a two-stage micron-submicron microstructure shape can be formed on the surface of the implant. The two-stage micron-submicron microstructure shape is prepared on the surface of the titanium alloy dental implant, so that the method achieves the property of guiding the adhesion of osteoblasts, can simulate natural histomorphology in vivo, can guide the bone matrix formation on the surface rapidly, and can promote the formation of good synosteosis. Therefore, the titanium alloy dental implant can promote the formation of new bones, can short the healing time, and can achieve the ideal effect that the titanium alloy dental implant can take on the recovery function as soon as being implanted further.