Vernier caliper for steel rail section dimension detection

The utility model belongs to the technical field of measuring instruments, particularly relates to a vernier caliper for detecting the size of a section of a steel rail, and aims to solve the problems that the conventional vernier caliper for detecting the size of the section of the steel rail is inconvenient to block up, and the whole height of the vernier caliper cannot reach the measured height when a workpiece is too high, so that the operation is not convenient enough. According to the scheme, the device comprises a base and a main ruler, the outer side of the main ruler is slidably sleeved with a sliding base, a fixed clamp and a movable clamp are fixedly installed at the bottom of the main ruler and the bottom of the sliding base respectively, an installation plate is fixedly installed on one side of the main ruler, a sliding hole is formed in the top of the installation plate, and a transverse groove is formed in the side wall of the sliding hole; a vertical plate is fixedly mounted on one side of the