The influence of the microstructure of polycarbonate (PC) on performance was systematically investigated by both experimental method and molecular simulation. Yield stress, impact strength, molecular weight, and transmittance were used to distinguish the degradation processes between different PCs, and thermal degradation kinetics was studied to obtain the activation energy. At the molecular level, through 13 C nuclear magnetic resonance (NMR) spectroscopy, it was observed that PCs have a more polar group of benzene rings, resulting in the high density, dielectric constant, and tensile modulus. Meanwhile, molecular dynamics (MD) simulation was employed under a polymer consistent force field force field. Specific volume and mechanical property were analyzed to investigate the thermodynamic property. The molecular dynamics simulation and experimental results on half decomposition temperature ( T 1/2 ), refraction index, flow activation energy, average density, cohesive energy density, glass transition temperature ( T g ), and elastic modulus had good agreement. Therefore, it was indicated that the molecular simulation could successfully study the characteristics and properties. The fundamental studies would be expected to supply useful information for designing materials and optimizing processing technology.