A negative pressure sealing drainage system for surgical treatment of deep cavity wound includes: a columnar porous foam drainage piece, a wave-form sealing cover which is extendable and retractable, a medical film, a drainage tube, a fluid storage container, and a negative pressure source. The columnar porous foam drainage piece is a hydrophilic foam, and is enclosed within the wave-form sealing cover. One end of the drainage tube is inserted into an upper portion of the columnar porous foam drainage piece. A flap provided along a circumference of the bottom-most end of the wave-form sealing cover adheres to skin surrounding a deep cavity wound. An upper end of the wave-form sealing cover is provided with a tube-shaped connection opening sealingly connected to the drainage tube communicating with a connection tube via a straight-tube fitting and inserted into the fluid storage container. The fluid storage container communicates with the negative pressure source via a connection tube.
