To study the effect of corrosion on the axial compression performance of the upright tube of steel tubular scaffold with couplers, the surface morphology of steel tubes with different corrosion ages was tested to analyze the influence of corrosion on the surface morphology of the inner and outer walls of steel tubes, and the degradation law of mechanical properties of corroded steel was discussed through the monotonic tensile test of corroded steel tube. The calculated formula for the stability of the corroded steel tube was proposed through the results of the axial compression tests. The results show that the distribution of pit corrosion on the surface of steel tube develops from independent pits to ulcer-like pit groups with an increase of the quality loss rate of steel tube. The pit corrosion ratio, the average arithmetic height, and the root mean square height of the outer wall are higher than those of the inner wall in varying degrees. Randomly distributed and different sizes of pits will cause the decrease of the strength and plastic deformation ability of the steel. Compared with the decrease in strength, corrosion has a more severe impact on the plastic deformation ability of steel. The axial compression failure mode of steel tubes with different corrosion degrees is the overall bending instability. As the mass loss rate increases, the ultimate load decreases linearly, and the axial displacement value corresponding to the peak load point decreases gradually.