The invention provides a pressure testing system. The pressure testing system includes a supporting device and a pressure loading device used for loading pressure to a sample. The supporting device includes a horizontally-arranged bearing plate and a support member vertically mounted on the bearing plate. The pressure loading device includes a loading plate, a liquid storage tank, a liquid feedingpipe and a liquid discharging pipe, wherein the loading plate is in horizontal fixed connection to the support member, the liquid storage tank is located on the loading plate, and the liquid feedingand discharging pipes are inserted in the liquid storage tank. According to the pressure testing system, a testing error due to the phenomenon that the range of a conventional testing machine is far larger than the compressive strength of a similar material is avoided. The pressure testing system achieves linear loading and unloading of an axial load in high precision, accurately measures the compressive strength and ultimate compressive strain of the similar material, and ensures the similarity between the similar material and an original material.