In a multi-channel supply chain composing of a dualchannel retailer and a pure online retailer, a Stackelberg masterslave countermeasure game model with the pure online retailer as a leader and a Stackelberg masterslave countermeasure game model with the dualchannel retailer as a leader were built respectively. Then we focused on two factors including the electric market scale and the proportion of the dual-channel retailer’s electronic market scale accounting for total electronic market scale, and studied the impact of the factors on the optimal pricing of supply chain members in different strategies of pricing timing. Finally, the changing trends of the prices of the channels in the equilibrium were discussed with numerical analysis. The results indicate that the optimal pricing level of both retailers’ electronic channel increases with the increase of their respective electronic market scale. If the pure online retailer sets the direct price before setting the price for the dual-channel retailer, the optimal pricing strategy of the dualchannel retailer is to adopt the low-price strategy of omnichannel firstly, and after the market scale of electronic market is expanded to a certain extent, the low-price strategy of traditional channels will remain unchanged and the price of electronic channel will be gradually increased.