The present invention provides a surface modification method of stereo objects and a sealing gasket for an injector. By using the surface modification method, good sliding performance is obtained, the durability in repeated sliding and sealing performance of the stereo object are improved. The surface modification method of stereo objects includes: step 1, dipping a plurality of stereo objects in a liquid containing photopolymerizable monomers; and step 2, forming polymer chains on the surfaces of the plurality of stereo objects through using light radiation to enable the photopolymerizable monomers to polymerize, while stirring the liquid containing the photopolymerizable monomers.
