Abstract: Due to its light-weight and high-strength, CFRP pipes can be used for the construction of long-span lattice structures. But the shortcoming of connection failure between elements restricts the utilization of its high strength. So CFRP-Aluminum composite pipe, made of aluminum pipe with wrapped CFRP sheets, is proposed here to improve the loading capacity and connection behavior. The composite pipes under axial force were firstly tested to obtain its loading properties and failure modes. Then eigenvalue buckling behaviors were studied with FEM to investigate the influence of different ply angles, thickness and sequence. An initial imperfection was introduced into FE model based on test results to further study the elasto-plastic buckling behaviors of composite pipes influenced by different slenderness ratios, ply angles and thickness. Finally, based on the tested and numerical analysis results, a formula to calculate the buckling load of composite pipes under axially compressive load is obtained by correcting Perry formula.