On the basis of the speed regulation principle of differential epicyclic gears,a hydraulic hybrid cutting transmission system for the drum shearer with speed regulation is designed.Then,according to the system composition,the mathematical models of key parts and their speed control methods are constructed respectively.Finally,the dynamic characteristics of hydraulic motor and drum and the cushion property of the designed system are analyzed by using AMESim.The results show that ( 1) the designed system can regulate the speed of drum shearers,which makes the new machine achieve better cutting performance in complex working conditions in comparison with the traditional drum shearer of constant speed; ( 2) the hydraulic motor and drum have high response speed and can accurately track the goal speed; and ( 3) the designed system can cushion the shock caused by mutation loads.