The present invention provides a diaphragm type fluid booster, mainly composed of a rotary directional valve, a booster cylinder, and a unit that provides power fluid. The booster cylinder has a duplex working chamber, where the left and right cylinder membranes are clamped between the cylinder body and cylinder head to form a chamber for the movement of the left and right membranes. The reversing valve core is rotated by the reversing valve motor to achieve alternating communication between the left and right cylinder flow channels through the total inlet and outlet of the reversing valve. The inner membrane of the chamber is deformed by the pressure difference between the two sides of the fluid, and the volume of the chamber on both sides of the membrane changes periodically, thereby achieving fluid boosting. The power unit can be provided by any system with stable power fluid delivery function such as oil pump, water pump, air pump, etc. The power unit and the boosting unit are separated, and the existing power unit can be fully utilized for boosting, forming a mobile boosting system. Diversified and standardized power units make it easy to form modular new products.
