For the situation that manufacturer's electronic direct channel and traditional retail channel sell homogeneous products in a vertical dual-channel supply chain, under price substitution coefficient perturbation, service level substitution coefficient perturbation, and price substitution coefficient and service level substitution coefficient simultaneous perturbations, demand models and profit models are built. Then by using the optimal profit condition, three optimal strategies in three different perturbation situations are proposed. The result shows that, when perturbation and keit within a certain range, by keeping the yield, the price and service level of the two channels can be adjuited. When the peturbation exceeds a certain range, by changing the yield, the price and service level of the two channels can be adjusted in order to obtain the optimal profit in corresponding perturbation situations.