Abstract: To improve the speed performances of tubular permanent magnet linear motors（TPMLM） under mismatched disturbances, a novel sliding mode control based on the internal model（IM-SMC） strategy was proposed. The internal model controller was used to transform the TPMLM drive system into a first-order inertial system. Hence the performance of quick response without overshoot was achieved. The system dynamic response time is directly determined by the adjustable parameter a. Therefore, the dynamic performance becomes easy to design. A second-order observer was used to estimate the mismatched disturbance, and then the estimate value was introduced into the design of the sliding mode surface.Combined with the observer, the TPMLM system can be robust to mismatched and matched disturbances. The feed-back current was adopted in the design of the speed controller. Thus,the speed and current can be both controlled by only one controller. The effectiveness of the proposed strategy was verified by the simulated and experimental results.