In order to study the influence of oil and gas temperature variation on characteristics of a hydro-pneumatic spring, the test bench of the comprehensive performance and the temperature test system of the spring were designed, and a vibration model was established. Then, the approximate analytic solution of the vibration model was obtained using a combination of the equivalent linearization method and Taylor expansion. The mathematical model with the temperature coefficient was closer to the actual situation than the experimental data was. Based on this, analysis of the influence of temperature variation on the damping and stiffness of the hydro-pneumatic spring was conducted. The results showed that damping decreased as oil temperature increased, and the spring damping effect was weakened. Moreover, stiffness increased as nitrogen temperature increased, and the load bearing of the spring was reduced.