For full-bridge LLC resonant converter, intermittent control strategy is an effective means to improve its light load efficiency. An improved intermittent control method was proposed to solve the problems of limited efficiency improvement and large output voltage ripple in light load state of converter by traditional intermittent control. This control method fixes the intermittent conduction time and makes the converter work at the resonant frequency during the intermittent conduction time, which further improves the light load efficiency of the converter and reduces the output voltage ripple. In order to verify the feasibility of the proposed method, a simulation model was built and the simulation waveforms of the traditional intermittent control strategy and the improved intermittent control strategy were compared and analyzed, and an experimental prototype with rated power of 100 W was made. The simulation and experimental results show that the output voltage ripple of the full-bridge LLC resonant converter with the improved intermittent control strategy can meet the engineering requirements, and compared with the traditional intermittent control strategy, the efficiency under light load is improved by up to 4.1%.