Hydraulic indexing tool is used to drive the washing sub for full circumferential washing. By controlling the displacement of pumping fluid, the tool can rotate axially by 45° or 60° each rotation. When the pumping fluid displacement reaches or exceeds a certain value, the lower part of the tool moves down and rotates, at this point, the pumping fluid can be flushed through the washing sub at this displacement. When the fluid displacement is lower than a certain value, the lower part of the tool moves up and completes a rotation and repeat the operations to complete the 360° washing operation. And various forms of washing subs are supplied.