The dynamic model of supply chain dual-channel with e-markets is established, including the dynamic controlling process of Internet channel and traditional channel, in which the inventory level is state variable and the produced quantity and supplied quantity are controlling variables. The bullwhip effect of dual-channel is described, and the H infin control strategy for controlling the bullwhip effect is advanced under the worst disturbing by demands. Combining with the practices of e-business in Shanghai Baosteel Yichang Co., the simulating calculation and analysis were carried out, and the controlling effect of Hinfin control algorithm for dual-channel is proved out