The invention discloses a protection apparatus for a precise electronic alarm device in a hydrogen phosphide elimination environment. Main components of the apparatus are made from high-molecular materials after flame retardation processing and fasteners and embedded parts are made of anti-corrosion-coating-layer-based metal materials, so that the protection apparatus has the excellent anti-corrosion and fireproof performances. Besides, in order to protect a precise electronic alarm device from corrosion of hydrogen phosphide gas, the protection apparatus has high visuality and operability. The protection apparatus is designed to a totally-enclosed case body; a box cover is formed by embedding of an imported ultra-thin quartz glass material and packaging is carried out by a special sealant, so that complete sealing and visuality can be realized and the glass can be broken easily in an emergency state like a fire accident and thus the internal device can be operated. According to the wiring characteristic of the protected equipment, power and control line interfaces are formed in case body thread holes. Because of the excellent anti-corrosion and security performances, the provided protection apparatus can be applied other severe environments like a corrosive environment, a high-humidity environment, or an outdoor environment.