Fire and explosion protection structure installed on cable intermediate head, and use method thereof

The invention discloses a fire and explosion protection structure installed on a cable intermediate head, and a use method thereof, and belongs to the technical field of the fire and explosion protection of a cable head. The fire and explosion protection structure comprises an outer box body, an assembling end cover, a disposable sealing end cover and an inner sealing ring, wherein the longitudinal assembling surface of the outer box body is provided with a double-channel sealing structure; the assembling end cover and the outer box body adopt an embedded sealing structure; the disposable sealing end cover and the inner sealing ring are arranged on the assembling end cover and are used for sealing a gap between a cable ring surface and the relevant cooperation surface of the assembling end cover; the outer box body is provided with a sealant injection pipe and a vent pipe; and the cable is completely covered with a cable fire protection wrapping tape after the cable is connected by the intermediate head, and is arranged in the outer box body, and fire protection sealant is injected into the outer box body through a sealant injection pipe. On an aspect of operation, firstly, carbon dioxide or nitrogen is used for discharging air in the outer box body, and then, the fire protection sealant is injected into the outer box body to carry out high-pressure sizing. The fire and explosion protection structure carries out pressure maintaining sizing on the fire protection sealant through the outer box body to realize the sealing protection of the cable head, a compact filling layer can be formed on the periphery of the intermediate head, the defect of poor fire protection performance durability and reliability is eliminated, and the fire and explosion protection structure is low in cost and is favorable for popularization.