A method for solving bimetallic film coefficients using surface plasmon resonance (SPR) phase difference experimental data with fixed wavelength and multiple incident angles is presented to simplify and quickly solve the thickness and optical constants of metal films in this paper. The purpose is to extract unknown parameters from the phase difference between P-and S-polarizations of the reflected light occurred at the metal/dielectric interface. The results of bimetallic layer film's thickness and optical constants obtained by our method are in better agreement with that of spectroscopic ellipsometer (SE) measurement method. Therefore, the approach reveals the possibility of retrieving the thickness and optical constants from the measurement results of the phase difference for multilayers, and makes it be a much better option to be employed for further film's parameter analysis applications.