Poly(methyl methacrylate) (PMMA) is a thermoplastic polyester with excellent properties such as lightweight, low price, biocompatibility, and so on. However, its extensive utilization is restricted by the deficiencies of brittleness and poor mechanical properties. In this study, high-performance PMMA films enhanced by methylcellulose (MC) were fabricated by a simple procedure at ambient temperatures. The effects of PMMA/MC mass ratio and thermal compression treatment on mechanical properties (tensile strength and elongation) were systematically investigated. The PMMA/MC films showed remarkably enhanced mechanical properties compared with neat PMMA. The tensile strengths of the PMMA/MC (3:97) and PMMA/MC (1:1) films are higher than that of the PMMA/MC (9:1) film by about 471 and 83%, respectively. The mechanical properties were also improved after thermal compression treatment. Importantly, the PMMA/MC films could be recovered and reused. In addition, the morphologies, crystalline state, and chemical structures of the films were investigated by scanning electron microscopy, X-ray diffraction, and 13C NMR spectroscopy. The films are expected to be used as sustainable and potential alternatives to petroleum-based polymer film products because of their simple preparation procedure, high-performance mechanical properties, excellent recycling, eco-friendly features, and scale manufacture.