In view of severe corrosion problems of reinforced concrete bridge pier columns in strong saline soil / salt lakes of Western China,a new type of composite structure "steel reinforced polyethylene plastic pipe(SRPE) confined reinforced concrete column" is proposed, In order to study the mechanical properties of specimens under eccentric load, the 8 SRPE confined reinforced concrete columns and 4 unconfined control columns were tested subjected to eccentric load, and the influence of design parameters such as pressure level of SRPE pipe, eccentric distance and slenderness ratio on the mechanical properties of specimens was analyzed subjected to eccentric load., The bearing capacity calculation equation about SRPE confined reinforced concrete columns subjected to eccentric load is given for reference of engineering application. The results show that the SRPE pipe can significantly improve the extreme bearing capacity and ductility of the reinforced concrete column under eccentric load; the higher the pressure level of the SRPE pipe is, the better the improvement effect of bearing capacity is, but the improvement effect of ductility is not obvious;the ultimate bearing capacity of specimens decreases with the increase of eccentricity and slenderness ratio. The ductility of specimens decreases with the increase of slenderness ratio; The peak deflection in the column of the specimen is much larger than that of the control specimens, and it increases with the increase of eccentricity and slenderness ratio; The lateral deflection curve of specimen under ultimate load is close to sinusoidal half-wave curve.