Under the environment of smart grid construction, it will become a mainstream to supply power based on users’ demand. Firstly, this paper establishes the users’ demand model and proposes three demand indicators of emergency, including security demand, economy demand, and quality demand. At the same time, it presents the methods to measure different users’ demand levels. Then, based on the needs of different users, it proposes emergency power optimization model which aims at maximum users’ demand satisfaction. Finally, through solving the optimal configuration by the mixed integer linear programming algorithm, it obtains the configuration scheme of mobile emergency power, verifying the feasibility, superiority and its significance of the proposed model.