Abstract : This paper introduces control of hydraulic thruster for remotely operated vehicle (ROV) trencher which is a sort of heavy-duty work class. This ROV trencher carry out cable burying and maintenance duties on the seafloor mainly. It is operated by hydraulic system including hydraulic powered unit (HPU) and eight thrusters (four horizontal, four vertical) to have six degree of freedom (DOF). We can control the URI-T using two type of control input like joystick and jog dial, and there has difference input range. Moreover, the URI-T has two limitations with saturation for thruster and deadzone for valvepack. Additionally, this thrusters has difference in output rpm from the same input power because of oil temperature, its own friction, and difference of an oil pipe distance to each thrusters from the source. There are unstable factors to control the URI-T efficiently during operating. In this paper, we suggest proportional controller for hydraulic thruster to stabilize URI-T. We are modeling the propulsion system and simulating the performance of the controller. After that, we apply this controller to the ROV trencher and take a test to verify performance in the water-tank. As the results, the thrusters is working well using joystick and jog dial, and the rpm of thruster does not exceed the max rpm and deadzone is also controlled.