The invention discloses an aircraft generating a larger lift from its interior. The fluid channel inside the aircraft communicates with the engine and the ports on the upper surface of the outer shell. With the powerful suction of the engine, the fluid on the upper surface of the outer shell is quickly sucked into the fluid channel via respective ports under conditions of long path, large area, high speed and low air pressure, which results in large lift from the interior of the aircraft. In the course of generating the lift, the fluid resistances of the fluid wall and the fluid hole are sucked into the fluid channel through the ports at the front and the surrounding area of the aircraft, then high-speed fluid is emitted from the rear port. This approach contributes greatly to the transformation of the existing aircraft. The unified big wing significantly improves the lift, the speed and the carrying capacity of the existing aircraft with lowered energy consumption.