Comprehensive performance tests are conducted on a certain domestic heavy hydraulic rock drill with double damper system in order to find the reasons of powerless impact and airframe fever reasons. First, the impact energy is measured by the stress wave test, and the pressures of each chamber is monitored, including the piston’s front-chamber and rear-chamber, shuttle valve’s left-chamber and right chamber, damper system’s first-stage and second-stage chambers. Then, the impact piston’s moving law is derived according to the data, and the damper system’s working condition and damping piston’s equilibrium position are calculated based on the law. The results indicate that the shuttle valve work properly, the damping piston’s equilibrium position is reasonable, and the prototype’s impact powerless and airframe fever are caused by the lag hit. Finally, an improved method to shorten the bushing length is proposed to improve the rock drill’s property by eliminating the impact powerless and alleviating the airframe fever.The comprehensive performance test provides an effective means for rock drills’troubleshooting.