Abstract: The calculation steps of eccentric compression members in the current GB50010-2002 are tedious. A unified calculation method is derived to connect axial compression, eccentric compression and pure bending. The unified formula has a definite physical meaning and fit the experimental data well. The step of judging the type of eccentricity can be canceled and the calculated reinforcement area can be returned to the unified formula for checking. In the code M_u-N_u curve, a sharp point appeared at the junction of the large eccentric compression curve and the small one, and the small eccentric compression curve could not be connected with the axial point. Whereas the unified M_u-N_u correlation curve is a continuous smooth curve connecting the three force states. The unified M_u-N_u curve is in a good agreement with the Code curve. The results show that there is a reinforcement mutation between the small eccentricity formula and axial compression formula of the code. The small eccentric formula near the axial compression point is not safe. The reinforcement calculation of the unified formula has a good transition and can meet the demand of GB 50068-2001.