This paper studies marketing mix decision model of price and advertising in duopoly market. Firstly, market response model of advertising is the constructed, and effective advertising input range is calculated based on market forecast results. Secondly, the combination principle of price and advertising is studied, and the marketing mix model is built. Thirdly, game theory is used to establish the two-stage game of price and advertising, and the solution is given. Meanwhile, modern information technology is used do develop the marketing mix decision support system, so that the effectiveness of the marketing models can be proved and put into practice.