The invention belongs to the technical field of design of explosion phenomenon observation devices, and provides a sealing protection and opening method of an observation device under the action of explosion impact. An anti-explosion end cover, a sealing end cover and a device body constitute a closed cavity, and a pushing device and the observation device are placed in the cavity. The pushing device and the observation device are filled and fixed with flexible filler, no rigid contact exists between parts, after explosion occurs, the anti-explosion end cover and the sealing end cover are pushed out in sequence by the pushing device to realize opening, and the observation device is then pushed out to observe the explosion phenomenon. The protection method is mainly used for the observationdevice pre-placed in a closed space, and the observation device can be effectively sealed and protected at the moment of the explosion and is opened after the explosion occurs.