A hydraulic servo masterslave robot was designed and force bilateral servo control algorithm was studied. Because of the features of the common symmetry servo valve, the master manipulator can not drive the actors directly and pressure information of the master manipulator is needed to drive the actors through the controller. This process greatly affects the response speed of the control system. The force differential signal of the master and slave was used to control the slave manipulator and the position differential signal of the slave and the master was used to drive the master manipulator. This new control strategy improved the response speed of the master-slave control system. The slave’s interference situation could be decided based on how the master followed the slave. Additionally, the new control strategy changed the common control mode that the slave followed the master, and the master felt the slave’s force. 