The temperature perturbation being considered, the transmission matrixes of the reflected and refracted light beams on the prism surfaces have been modified. According to the self-consistent theory of the laser ring cavity, a physical model of the intra-cavity light transmission has been established considering the temperature disturbance in prism laser gyroscope, and the influences on the frequency variation, scale factor and other parameters have been analyzed. The theoretical analysis shows that when the temperature varies from －40℃to 70℃, the changes of the optical cavity-length, frequency offset, and scale factor are 10.04 μm, 0.011MHz and 1.96×10－10, respectively. An experimental system of the prism laser gyroscope has been established whose temperature can be changed, and the experimental results agree with the theoretical values.