The invention discloses a hydraulic synchronous jacking device of a die carrier system. The hydraulic synchronous jacking device comprises an upper supporting cross beam, a lower supporting cross beam and a jacking oil cylinder connected between the upper supporting cross beam and the lower supporting cross beam, wherein the jacking oil cylinder is placed upside down and passes through the main body of the upper supporting cross beam from bottom to top; a cylinder flange plate for connecting the cylinder body of the jacking oil cylinder is welded on the lower part of the cylinder body of the jacking oil cylinder, and is connected with a cross beam flange plate, which is welded on the lower surface of the main body of the upper supporting cross beam, through bolts; the upper surface of themain body of the upper supporting cross beam is provided with an upper supporting cross beam elongated slot, and the cylinder body of an upper cantilever outrigger driving cylinder is also fixedly connected to the upper surface of the main body of the upper supporting cross beam; and the upper surface of the main body of the lower supporting cross beam is provided with a lower supporting cross beam elongated slot, and the cylinder body of a lower cantilever outrigger driving cylinder is also fixedly connected to the upper surface of the lower supporting cross beam. The hydraulic synchronous jacking device saves the vertical construction space for a low-position jacking die carrier system to ensure that the assembly height of a steel platform is greatly reduced, so the hydraulic synchronous jacking device is convenient for construction, and can improve the construction efficiency.