A series of low-cost fluorine-containing co-polyimides CPI-1~CPI-4 are prepared using 2,2'-bis(trifluoromethyl)benzidine (TFMB),4,4'-Oxydianiline (ODA) and 3,3',4,4'-Diphenyl ether tetracar-boxylic acid dianhydride (ODPA) as monomers and m-cresol as a solvent. The structure of this series of fluorinated co-polyimides were characterized by infrared spectrometer, nuclear magnetic resonance spec-tromete. The series of fluorine-containing co-polyimides can be dissolved in organic solvents such as DMSO, DMAc and CHCl3 at room temperature, and have good solubility and film forming properties. The prepared film has excellent optical transparency, and the light transmittance at a wavelength of ultraviolet light of 400 nm is more than 70%.The series of fluorine-containing co-polyimides also have excellent thermal stability, the initial decomposition temperature is more than 500 ?C, the mass residual percentage at 800 ?C in N2 atmosphere is above 52%, and the glass transition temperature is in the range of 166-170 ?C.In addition,these kinds of the co-polyimide film prepared in the tensile strength of 89.8~105.3 MPa, an elastic modulus between 1.3 ~ 1.7 GPa, the elongation at break in the range of 9.7 to 18.4%, showing good mechanical properties.