In order to solve the contradiction between capacity and fairness in orthogonal frequency division multiple access(OFDMA) systems, this paper proposes a strategy of maximizing the system capacity by considering fairness during the subcarrier allocation and ensuring fairness threshold during the power allocation. The proposed strategy firstly combines the current subcarrier method with Hungarian algorithm to preferentially maximize the system capacity and then take into account fairness among users. After that, a fairness threshold based artificial bee colony algorithm for power allocation is applied to preferentially ensure fairness threshold and then maximize the system capacity. The experimental results show that the subcarrier allocation method of the proposed strategy can not only maximize the system capacity and consider fairness among users, but also improve both the system capacity and fairness among users at the same time, and that the artificial bee colony power allocation method of the proposed strategy has better robustness and global optimization ability, and can achieve the required fairness threshold and maximize the system capacity even when the number of users is larger. The study results verity the effectiveness of the proposed strategy.