The invention discloses a tank hydraulic fixture. The tank hydraulic fixture is characterized in that a first rotation angle cylinder padding block, a second rotation angle cylinder padding block and a third rotation angle cylinder padding block are arranged on one side of a bottom plate; a first rotation angle cylinder is arranged above the first rotation angle cylinder padding block; a bevel mounting plate is arranged on the other side of the bottom plate; a fourth rotation angle cylinder and a fifth rotation angle cylinder are arranged on the oblique surface of the bevel mounting plate; a first locating block is arranged at the part, on one side of the first rotation angle cylinder padding block, of the bottom plate; a second locating block is arranged at the part, on one side of the second rotation angle cylinder padding block, of the bottom plate; and a third locating block is arranged at the part, on one side of the third rotation angle cylinder padding block, of the bottom plate. The tank hydraulic fixture has the advantages that (1) the concept is ingenious, the implementation cost is low, and the maintenance and repair cost is low; (2) the locating is accurate, and the working state is stable; and (3) a three-point adjustable clamping mechanism is adopted, the operation is convenient, and the control accuracy is high.