Price models with regime switching can describe the impact of macroeconomics. However, when constructing an equivalent martingale measure to price financial derivatives, the equivalent martingale measure obtained by the traditional Esscher transform considers only micro-marketing risks but not macroeconomic risks represented by the regime switching. In addition, the classical geometric Brownian motion can not characterize higher peak and fat tail phenomena of asset returns. In this paper, firstly, by using a Markov process and a non-extensive maximum entropy distribution, a new price model which can describe both the phenomena of higher peak, fat tail and regime-switching is constructed. Then, by utilizing the martingale theory and the product of the price process of micro market and the Markov process of macroeconomics, a new method for constructing equivalent martingale measure is provided. The equivalent martingale measure obtained by this approach includes two kinds of risks: micro-marketing risks and macroeconomic risks. Finally, under the resulted equivalent martingale measure, the necessary and sufficient conditions are given with which the discounted asset price process can become a martingale. The results provide a theoretical basis for further studying derivative pricing and risk control.