The magnetic-axis radial position ${R}_{M}$ is one of the most important parameters of the reliable, real-time, plasma control system. The magnetic-axis model suitable for the non-circular cross section plasma is studied based on the magnetic-axis model of the circular cross section plasma. The model is verified by the discharge parameters of Experimental and Advanced Superconducting Tokamak (EAST) ( $k \sim $ 1.4–1.9, i.e., non-circular cross section). The offline magnetic equilibrium code, EAST equilibrium fitting (EFIT), has been selected as the reference calculation for magnetic-axis radial position. The error of ${R}_{M}$ compared to the EAST EFIT code reference value is reported and discussed for the circular and non-circular cross-section plasmas in EAST. The analysis results show that the developed magnetic axis model is available to calculate the magnetic axis radial position value, with the average error $\overline {\Delta R_{M}}\approx 0.015$ and 0.025 m for the ${\beta }_{p}{ and ${\beta }_{p}{>2}$ cases, respectively. The error level depends on the elongation ratio $k $ and the poloidal plasma beta ${\beta }_{p}$ in the high- ${\beta }_{p}$ cases.