Separable pillar type lightning arrester capable of preventing water vapor from entering

The invention discloses a separable pillar type lightning arrester capable of preventing moisture from entering, and belongs to the field of lightning arresters. Comprising a lightning arrester body and a sealing cover, multiple sets of fixed connecting plates are fixedly installed at the bottom end of the lightning arrester body, the outer surface of the top end of the lightning arrester body is connected with a second connecting ring, the outer surface of the bottom end of the sealing cover is connected with an abutting ring, the outer surface of the abutting ring is wrapped with rubber, and the abutting ring is rotationally connected with a first connecting ring through the sealing cover; in the rotating process, a sealing cover moves towards the bottom of a second connecting ring, so that a pressing block extrudes a first extrusion block in a clamping ring, a second extrusion block extrudes a first rubber air bag, and the first rubber air bag and the inner wall of the first connecting ring extrude; theref