The traditional steel spring is replaced with high-strength and light-weight titanium alloy spring for weight loss, which not only need meet the requirements of the service life of the spring, but also meet the spring requirements of three-way stiffness and installing space. The theoretical calculations and tests showed that : the three-way stiffness and installing space of the titanium alloy spring could be consistent with the original steel spring; The fatigue life of the titanium alloy spring exceeded 2 million times; The processing was also similar to the original steel spring, just different in specific control index. The titanium alloy spring could replace steel spring absolutely.