The invention discloses a preparation method of a polytetrafluoroethylene/polyacrylate core-shell emulsion for a pressure-sensitive adhesive. The preparation method comprises the following steps: a, preparing a seed preemulsion; b, preparing a shell-layer monomer preemulsion; c, preparing the core-shell emulsion. By the preparation method, with a polytetrafluoroethylene emulsion as a seed and a copolymer of acrylic monomers as a shell, a composite modified emulsion adopting a core-shell structure is prepared, and the external seed polytetrafluoroethylene is creatively introduced. Through control of the addition amount of the PTFE seed in the seed stage and the using amount of a shell-layer crosslinking agent, the pressure-sensitive property of the pressure-sensitive adhesive is controlled.By the preparation method, the controllability of morphologies, compositions and structures of latex particles is achieved, the experimental operation is simple, and environment pollution is avoided.