Disclosed are an isentropic booster and a method thereof. The booster comprises a main body pump having a chamber provided with a fixed division plate, a left piston, a right piston and a connecting rod separating the chamber into a plurality of independent booster chambers. The connecting rod passes through the division plate and connects at its two opposite ends with the left piston and the right piston. The volume of the booster chambers is changed with the movement of the left piston and the right piston. A part of the plurality of the booster chambers connect between high-pressure gas source and a medium-pressure gas pipeline network, and the rest of the plurality of the booster chambers connect between low-pressure gas source and the medium-pressure gas pipeline network. The isentropic booster of present invention improves efficiency of using high-pressure gas.