The invention provides a gas gap pressure stabilizer. A gas rectification and pressure stabilization device is designed for a gas lubrication, resistance reduction and energy saving device for a ship.The stabilizer comprises N pressure stabilization cavities in a ship baseplate, m gas jetting holes are formed in the bottoms of the pressure stabilization cavities, and the N pressure stabilizationcavities are connected with gas supply equipment separately and fixed in the inner side or the outer side of the ship baseplate in the width direction of the ship, wherein m is larger than or equal to3, and N is larger than or equal to 1; the spacing distance between every two pressure stabilization cavities is 5-150 m, the shape of the cross section is rectangular, square, semicircular, semi-oval or wing-shaped, the interiors of the N pressure stabilization cavities are smooth, the N pressure stabilization cavities are independent from one another, and the volume (V) of the pressure stabilization cavities is equal to the specific value of CPQ to N, wherein Cp is a gas compression coefficient, Q is a gas supply amount of gas supply equipment, and N is the number of the pressure stabilization cavities; the gas jetting holes are formed in the bottom planes, parallel to the water flow direction, of the pressure stabilization cavities or formed in the ship baseplate in the pressure stabilization cavities.