Abstract: Tactical wireless network is a critical facility for intelligence, fire attack, search & rescue and other tactical actions. Affected by terrain, climate, enemy jamming, etc., it faces severe spectrum scarcity.Aim at efficient allocating spectrum in radio "single-hop access" organization mode; we formulate an optimization model to maximize spectrum utility and propose a joint optimization algorithm for radio association and spectrum allocation. A novel weight taking both radios' load intensities and SNRs into account has been designed. We solve the optimal association among wireless access nodes (WANs) and radios and optimal spectrum allocation among radios according this weight. The former alleviates the near-far problem when radios access WANs, and guarantees radios with heavy load intensity have priority to associate a nearer WAN. Also focuses on the fairness of spectrum allocation, the latter optimizes the overall system throughput. Simulation results demonstrate that, compared with static and adaptive spectrum allocation algorithm only considering the load intensities of radios, the proposed algorithm can improve the system performances effectively.