Abstract: In order to study the creep performance of concrete filled steel tube defect specimens, 7 groups of creep tests were carried out, and the curves of creep degree with load holding time before and after strengthening were obtained. The results show that compared with the non-defective concrete-filled steel tube, the creep degree of the defective concrete-filled steel tube increases to different degrees, among them, the creep increment of the specimens with debonding defects is much larger than that with cavity defects. The debonding defect weakens the interface bonding between steel tube and concrete, which weakens the stress redistribution effect of steel tube and concrete, and reduces the cooperative deformation capacity. The stress concentration of concrete at the cavity defect intensifies the generation and expansion of cracks, which leads to the dislocation slip of concrete and increases the additional deformation of concrete-filled steel tube. After grouting, the creep deformation of concrete-filled steel tube decreases. However, compared with concrete-filled steel tube without defects, the creep behavior of reinforced concrete filled steel tube is still reduced to some extent.