Before drilling into practical use, possible load influence on rig system should be tested first, to find the design deficiency or verify the work ability.In the designed drilling hydraulic loading control system, the hydraulic cylinder and hydraulic motor (pump) were used to export feeding force and torque, to simulate the actual working load state of drilling rig and to realize drilling rig laboratory simulation load test. Tests prove that the hydraulic loading system meets the demand of rig load test, load control is accurate and maintenance cost is low.