To provide a hydraulic actuator controller, capable of controlling a return liquid amount in a return liquid pipeline in a pressure reducing process further accurately and having superior practicality.

This hydraulic actuator controller controls increase or decrease of pressure of a hydraulic actuator 1 by a supply liquid amount in a supply liquid pipeline 2 or a return liquid amount in the return liquid pipeline 3. A variable discharge pump 4 for liquid feed is provided for normal liquid feed operation in the increase of the pressure of the hydraulic actuator 1 and also makes liquid feed operation when the pressure of the return liquid pipeline 3 positioned between a variable discharge pump 6 for return liquid and a opening/closing valve 7 for pressure reducing is lower than the set pressure. The variable discharge pump 6 is provided for normal liquid return operation in the pressure-reducing process of the hydraulic actuator 1 and additionally makes the pressure of the return liquid pipeline 3 set pressure, corresponding to the additional liquid feed operation of the variable discharge pimp 4 when the pressure of the return liquid pipeline 3 is lower than the set pressure.