Abstract: Bio-based polycarbonate (PIC) is limited by the rigid alicyclic skeleton and ether bond in the molecular chain, which leads to a low refractive index, high birefringence value and high water absorption. In this study, the high molecular weight and random distribution of bio-based copolycarbonate (PFIC) were synthesized from diphenyl carbonate (DPC), 9, 9-bis (4-(2-hydroxyethoxy) phenyl fluorene (BPEF) and isosorbide (ISB) by melt transesterification. The addition of Cardo monomer BPEF gives PFIC better optical properties, mechanical properties, thermal stability and hydrophobicity than PIC, thereby broadening the application of bio-based polycarbonate in the field of optical films. When the molar fraction of BPEF ranges from 22% to 70%, the PFIC films exhibit negative dispersion characteristics. Specifically, when the molar fraction of BPEF is 65%, this PFIC film demonstrates high refractive index (n_d = 1.620) and low birefringence (Δn = 0.00007). Furthermore, the orientation and birefringence value of PFIC films increase with the decrease of draw temperature, the increase of draw ratio and draw speed, but the birefringence wavelength dispersion is not affected.The result lays an experimental foundation for regulating the optical properties of polycarbonate films.