In order to improve the control accuracy of a certain type of artillery coordinator under complex motion conditions, an adaptive sliding mode control strategy based on disturbance observer was proposed for the hydraulic system of the coordinator. The sliding mode control can make the system follow the state trajectory of the sliding mode dynamic surface, and realize the nonlinear control of the system. An adaptive strategy is added to prevent the system from failure due to excessive sliding mode switching gain. On this basis, adding disturbance observer for feed forward compensation can reduce the influence of system parameter changes and unknown disturbances on the system, reduce chattering, and effectively improve the control performance. The joint simulation and experimental results show that the control strategy can improve the control accuracy of the system.