The invention belongs to the technical field of concrete-filled steel tube compression resistance and creep tests and in particular relates to a concrete-filled steel tube creep testing device considering initial stress of the steel tube. The concrete-filled steel tube creep testing device comprises a steel tube initial stress loading device and a lever-type concrete creep loading device, whereinthe steel tube initial stress loading device is arranged on a rigid foundation, a concrete-filled steel tube test block provided with a vibration wire strain gauge is arranged in the steel tube initial stress loading device, the steel tube initial stress loading device is arranged at the lower side of the lever-type concrete creep loading device, a structure capable of applying a loading force isarranged at one end of the lever-type concrete creep loading device, and the other end of the lever-type concrete creep loading device is connected with ground by virtue of a structure with length adjustable. The concrete-filled steel tube creep testing device provided by the invention has the advantages that each part is low in manufacturing and processing difficulty, construction is convenient,materials can be directly selected from a construction site, cost is relatively low, and safety and reliability are realized, so that the concrete-filled steel tube creep testing device provided by the invention has relatively great popularization and application value and a relatively good application prospect.