The invention relates to a method for improving biological activity of a pure titanium surface by using dopamine to be bonded with graphene oxide. The method comprises the following steps: successively carrying out ultrasonic cleaning on a pure titanium sheet of which the surface roughness Ra is not greater than 1micron by adopting acetone and deionized water; carrying out acid treatment by using a nitric acid, cleaning the pure titanium sheet by the deionized water, and then carrying out alkali treatment on a sample by using sodium hydroxide at 40-80 DEG C; preparing a dopamine-trihydroxymethyl aminomethane solution of which the pH is 8.5; soaking the processed pure titanium sample into the prepared dopamine solution, and standing the sample at room temperature for 12-24 hours; taking out the sample, cleaning the sample by using the deionized water, and drying the sample at room temperature, so as to prepare a titanium/dopamine sample; soaking the titanium/dopamine sample into a graphene oxide water solution and standing the sample at room temperature for 12-24 hours; and cleaning the sample by using the deionized water after taking out the sample, drying the sample at room temperature, so as to prepare a titanium/dopamine/graphene oxide sample. The method is simple to operate, green and pollution-free, mass production can be achieved, and a channel is expanded for surface modification of the titanium material.