The invention provides a preparation method of a surface-modified polyacrylate microsphere aqueous suspension, a polyacrylate microsphere type pressure sensitive adhesive, and an application of the aqueous suspension. The preparation method comprises the following steps: S1, adding a pre-emulsion I to a mixed solution containing a surfactant and water, and carrying out a reaction to obtain a polyacrylate microsphere aqueous suspension; and S2, adding a pre-emulsion II and an aqueous solution containing a water-soluble initiator to the polyacrylate microsphere aqueous suspension, and carrying out a reaction to obtain the surface-modified polyacrylate microsphere aqueous suspension. The surface- modified polyacrylate microsphere aqueous suspension prepared by the method has good comprehensive performance, and can achieve a superior balance in initial adhesion, peeling force, adhesion accumulation and microsphere transfer rate.