The performance in extracting wave power from an offshore OWC device with a surging front lip-wall and back lip-wall is explored and according to the potential flow theory, the matched eigenfunction method is employed to establish a theoretical model to solve the boundary value problem. Effects from the variation of symmetry lip-wall drafts, chamber breadth, and spring stiffness, on the optimal extraction efficiency and other parameters of the OWC with different moving components are compared and discussed. It is found that a relatively deeper wall draft is more beneficial for the power extraction when equipped with a surging front lip-wall within the interested wave frequency range. To improve the trapped energy and reduce the occurring of sloshing mode inside the pneumatic chamber for a surging front lip-wall, a medium chamber breadth is more desirable as it can significantly enhance the peak efficiency as well as the expansion of high-efficiency frequency bandwidth, while a surging back lip-wall model is inferior in this aspect. In addition, generally a relatively smaller spring stiffness and even stiffness of zero is more recommended for the front-wall than the back-wall surging motion as the former can make full use the positive effects of the surging mode.