Herein, a facile solution chemical route has been developed for synthesis of Ag2Se-based alloy nanocrystals. The maximum thermoelectric figure of merit reaches 0.7 at 317K for Ag2Se, which is the largest value reported by wet chemical method. Sn doping further improves ZT to 0.9 at 300K, realized by the simultaneous modulation of transport and thermal properties. Our results indicate that cycling and Sn doping are efficient way to enhance thermoelectric performance of Ag2Se.