The invention relates to an improved steel structure stand column. The improved steel structure stand column comprises a base, a column body, a top seat and a mounting bracket, the column body is mounted at the upper end of the base, the top seat is mounted at the upper end of the column body, and the mounting bracket is mounted on the middle part of the column body, the column body is of a U-shaped structure, and mounting holes are separately formed in the front side and the rear side of the column body from top to bottom; and the mounting bracket comprises a sliding block, a limiting plate, a clamping assembly and a mounting assembly, the clamping position assembly comprises a vertical plate, a moving plate, a clamping block, a moving spring, a shielding frame, an adjusting spring and an adjusting screw, and the base comprises a base plate, a fixing seat, a positioning frame and a stabilizer frame, and the top seat comprises a socket pipe, a clamping block, a supporting plate and a working plate. The purpose of fixing the members and the column body at the joint is achieved by the combination of the rigid connection and the elastic connection, the seismic resistance of the connecting position can be improved, and the number and position of the mounting bracket can be flexibly adjusted to meet different work requirements.