The section of steel column under axial compression presents the state of heterogeneous mechanics and its load condition changes after experiencing fire damage. Taking H-section steel column under axial compression commonly used in engineering for study object, in order to study the residual load bearing capacity after fire and consider the strength change of the material after high temperature and the influence of non-uniform temperature field on material properties and the stiffness degradation of member section, the eccentric effect of steel column under axial compression exposure to one-side fire was analyzed by using the method of equivalent section. The paper proposed calculation methods of the eccentricity and additional moment and further given a formula of residual bearing capacity of the column after fire. The rationality of the calculation methods was verified by the analysis of a calculation example. The method can be used not only to calculate the stability bearing capacity of steel column exposed to one-side fire under axial compression after fire, but also to provide new ideas for similar studies.