Objective: To explore the application value of dual chamber round tissue expander in immediate breast reconstruction. Methods: Sixteen patients, who had been provided immediate tissue expander/implant two-stage breast reconstruction using dual chamber round tissue expander in our hospital from March 2022 to October 2023, were involved in this study, and the relevant information was analyzed retrospectively. The overall design of the expander is a round shape, consisting of two equally divided semi-circular chambers. The two expansion chambers are connected by a silicone pad below and are respectively connected to their own water injection tubes. Both chambers are designed to expand unidirectionally towards the surface. The expansion principle, insertion process, and type of expander selection were investigated. The expansion effect and incidence of complications were summarized. The aesthetic effect of reconstructed breasts was evaluated from three aspects after stage Ⅱ surgery: the position of infra mammary fold, the breast protrusion, and the breast volume. Results: Among sixteen patients in this study, three patients were selected with the type of 400 mL expander and thirteen patients were given the type of 600 mL expander. The median time of tissue expansion was 4.0 (2.0, 5.0) months, with an average volume of expansion of (538.8±111.7) mL. The average expansion ratio of upper/lower chamber was 45.4%±8.4%. The position of the infra mammary fold needed not to be adjusted during the prosthesis exchange process. All the patients were applied anatomical prostheses, and the median volume of the prosthesis was 395 (345, 410) mL. One patient developed seroma during expansion period, who got improved after local aspiration. The average follow-up time was (9.0±3.6) months. 81.3% (13/16) of the patients achieved an aesthetic evaluation of "Good" in breast reconstruction, and 75.0% (12/16) of the patients got a grade Ⅰ or grade Ⅱ capsule contracture of the prosthesis. Conclusion: The application of dual chamber round tissue expander could effectively dilate the lower pole of the breast, personalize the expansion ratio of the upper and lower poles of the breast, and avoid the displacement of the expander during the expansion period. Therefore, it could provide a good foundation for subsequent prosthesis exchange.