With the improvement of people's living standard, car has become an indispensable means of transportation, and the specialized car service industry is developing rapidly. Therefore, for the car repair stores, it is the core issue to choose suitable location according to the characteristics of car owners and existing competition. This study puts forward a model aiming at the maximum profit rate considering choice preference of car owners, competition, consumption capacity of owners, and capital limit. Then, a genetic algorithm improved in four aspects is proposed to solve the proposed model. Finally, an example and a case study of Dalian expound the application of the proposed models and algorithms in practice. It proved to be effective to China's national conditions through the analysis of the results.