The application provides a polymethyl methacrylate product and a preparation method thereof. The preparation method of the polymethyl methacrylate product comprises the following steps: S1. mixing a resin matrix, a toughening agent, an antioxidant and a light stabilizer to obtain a mixture; the resin matrix comprises a polymethyl methacrylate resin; the toughening agent comprises a core-shell structure toughening agent and a polyester-based toughening agent; the core-shell structure toughening agent comprises a core and a shell layer; the core comprises polybutyl acrylate, and the shell layer comprises polymethyl methacrylate; S2. melt blending, extruding and granulating the mixture, and drying, injection molding, cooling and annealing. In the application, the core-shell structure toughening agent and the polyester-based toughening agent can synergistically improve the toughening effect.