Existing studies have shown that the seismic performance of the mortise and grouting sleeve mixed connection assembled square pier (referred to as the mixed connection assembled pier) is close to that of the integral cast-in-place pier. In order to further explore the axial compression performance of the mixed-connected bridge piers, the length, diameter and wall thickness of the steel pipe are used as the variable parameters,Carry out the axial compression bearing capacity test of 1 integral cast-in-place bridge pier (No. ZT) and 4 mixed connection and assembled bridge piers (No. GTA-0~GTD-0), The results show: The bearing capacity of GTA-0~GTD-0 specimens is 10.1%~14.4% higher than that of ZT specimens, and their ductility coefficients are all greater than that of ZT specimens; The axial compression bearing capacity of GTA-0~GTD-0 specimens increases with the increase of the diameter and length of the steel pipe, while the wall thickness of the steel pipe has a small effect on the bearing capacity of the specimen;The damage position of the assembled bridge pier moves upward with the increase of the steel pipe length, and gradually approaches the integral cast-in-place bridge pier, but the failure modes of the two are basically the same. Relevant research conclusions can provide reference for engineering design.