This paper presents three improved zero-voltage-switching of synchronous rectifier buck converter efficiency at light loads control strategies. Synchronous rectification control technology is suitable for direct application of low voltage output because the output rectifier diode with a MOSFET replacemet, with low conduction losses, can improve the overall efficiency of the circuit. Join the zero-voltage-switching, efficiency has been significantly improved,but under lightly loaded conditions, efficiency is poor. In this paper, three different control strategies, the zero-voltage-switching of synchronous rectifier buck converter in light load conditions improve efficiency at light loads.The possibility of this technology is confirmed.Also the feasibility of the proposed strategy is venfied.