Isolation guardrail for tunnel maintenance

The utility model discloses an isolation guardrail for tunnel maintenance, relates to the technical field of isolation guardrails, and aims to solve the problems that most of the existing isolation guardrails in the prior art are fixed in size, the length cannot be adjusted according to use conditions, the flexibility is poor, and the use is very inconvenient. Side plates are symmetrically arranged on the two sides of the guardrail plate correspondingly, telescopic inner cavities are symmetrically formed in the two sides of the interior of the guardrail plate correspondingly, shear fork assemblies are arranged in the telescopic inner cavities, second mounting boxes are mounted on one sides of the shear fork assemblies, and the second mounting boxes are fixedly connected with the guardrail plate through bolts; a first mounting box is mounted on the other side of the shear fork assembly and fixedly connected with the side plate through bolts, a first rubber soft plate is mounted on the front end face of the gua