A vacuum-based energy-saving large-capacity precision pressure regulation valve includes a base valve seat, a middle valve seat, and a pressure regulation seat. The base valve seat includes a main channel that receives a primary-side pressure and a secondary-side pressure to flow therein and includes a valve port piston arranged in the base valve seat to form a valve port opening. The valve port piston is rotatably coupled to a sealing straight rod that is coupled to a main diaphragm. The main diaphragm is clamped between the middle valve seat and the base valve seat to form a vacuum pressure chamber. A balance diaphragm is clamped between the middle valve seat and the pressure regulation seat. An atmosphere passage is connected to a space below the balance diaphragm. A guide passage and a feedback passage are in communication with the vacuum pressure chamber and the main channel.