The circular hollow GFRP (Glass Fiber-Reinforced Polymers)-recycled concrete-steel column is a new type of composite structure that is characterized by light weight, high strength, good corrosion resistance, and it provides a new idea for solving the problem of waste concrete pollution. However, there is a lack of research on the mechanical behavior of circular hollow GFRP-recycled concrete-steel long column. In order to study the mechanical behavior of the circular hollow GFRP-recycled concrete-steel long column, a finite element model of the circular hollow GFRP-recycled concrete-steel long column was established by applying ABAQUS finite element analysis software, and the validity of the model was verified based on the relevant experimental results. The working mechanism of the composite long columns is analyzed under the conditions of each factor by means of mid-span deflection curves and ultimate load bearing capacity that uses the slenderness ratio, eccentricity, and GFRP thickness as factors. The results indicate that in the initial stage, the lateral deflection of the composite long column is minimal, and its stiffness is high. As the load increases, the stiffness gradually decreases. After reaching the ultimate load bearing capacity, the load-lateral deflection curve decreases slowly, showing improved ductility and deformation. The effect of recycled coarse aggregate substitution ration on the load bearing capacity of the combined long column is minimal, when the length to recycled coarse aggregate substitution ration increases from 0 to 100, the ultimate load bearing capacity decreases by 14.9%, respectively;and the ultimate load bearing capacity decreases by 35.1%, 51.8% and 61.3% when the eccentricity distance(e) increases from 0 mm to 15mm, 30mm and 45 mm, respectively. The study provides a reference for the engineering application of GFRP-recycled concrete-steel composite columns.