Abstract: A portable emergency instant inflation device includes a box and a fastening plate with slots. The upper side of the box is provided with fastening hooks for engaging slots of the fastening plate. An inflation tube is formed at one end of the box. A tie string extends from the other end of the box to connect to a pull ring. A partition plate with through holes is disposed inside the box to divide the interior of the box into upper and lower spaces. The upper space contains a sac filled with citric acid solution while the lower space is filled with soda powder. The lower space further communicates with the inflation tube, which is internally provided with a valve flap. A slide cutter is further disposed in the upper space and has cutting edges slightly abutting the sac. The slide cutter is connected to the tie string via a cutter mount.