Abstract: The rotary hydraulic system of coalbed methane and rescue truck-mounted drilling rig is studied. The parameters matching of the valve back compensation rotary system and the output speed characteristics of the power head are analyzed. Based on the professional simulation software AMESim, the model of the valve back compensation rotary hydraulic system is established. Through theoretical analysis, it is concluded that the matching of LS pressure relief damper hole parameters of the load-sensing valve after the valve back compensation of rotary hydraulic system has a great influence on the load adaptability of the hydraulic system. Combining with dynamic simulation, the relationship between the parameters of damper holes and the load adaptability and response of the system is obtained. The test of the rotary system of ZMK5530TZJ100F truck-mounted drilling rig is carried out, and the correctness of the simulation analysis is verified by the test. The results show that the load adaptability of the rotary system is solved by matching the parameters of the damper holes, and the response and control accuracy of the system are improved.