In this study, a series of poly(methyl methacrylate) (PMMA) copolymer films were prepared via solution polymerization of methyl methacrylate (MMA) with butyl acrylate (BA) and lauryl methacrylate (LMA) as monomers. Mechanical properties, hydrophobic properties, and optical properties of the films were intensively investigated. The rheological results showed that the fluidity of the copolymer was considerably enhanced. When the monomer ratio of MMA:BA:LMA was 100:30:10, the copolymer film S4 showed the best overall performance with perfect optical transparency maintained. The results of the dynamic mechanical and thermal analysis suggested that the glass transition temperature (Tg) moved towards lower temperature, with enhanced ductility of the PMMA films. A large number of yield folds and crazes appeared on the cross-sectional surface of copolymer films through morphological observations, displaying the obvious characteristics of toughness fracture and obeying the energy dissipation mechanism of cracks shear band. The present study provided a facile way of preparing PMMA films with high toughness and light transmittance by appropriate selection of the monomers, which will be of practical significance for further studies on the replacement of triacetyl cellulose as a support film of polarizers.