A high-reliability, low-cost buoy–chain–sprocket wave energy capture device is proposed. Resonance theory is used to improve its wave energy capture efficiency and reduce its cost. The testing principle of the buoy–chain–sprocket model is proposed, and comparable resonant and nonresonant experimental floating body models were constructed based on finite depth linear wave theory and the resonance principle. Then the methods and results of the model experiments are described. Based on using Morison equation to calculate wave load, simulation and verification of the model experiment were conducted by using AQWA and OrcaFlex software. Finally, to eliminate the size effect and the impact of one-way wave energy collection, based on the simulation technology described above, sea-state prototype models of resonant and nonresonant buoy–chain–sprocket wave energy capture devices with one-way and two-way acquisition characteristics were constructed. Simulations were then conducted to get the maximum wave energy gathering efficiency. The research result indicates that the nonresonant buoy–chain–sprocket wave energy capture device with one-way acquisition has higher wave energy capture efficiency than the resonant buoy–chain–sprocket wave energy capture device.