The Olympic Games are always considered to have a substantial impact on the country's economic development so that every people living in this country will pay attention to it. They want to know whether their quality of life can be improved or how they should cope with the economic fluctuations. A detailed cross-country comparison of financial data from previous Olympic Games is provided in this work. A longitudinal comparison is used to determine whether economic growth rates have increased before and after the Olympic Games. By analyzing the data and related materials provided by the host cities of the summer Olympic Games in recent years, a regression model is also established in this paper to find out the impact of the Olympic Games on the host country. The conclusion is that the Olympic Games will not positively impact the host country's financial development and economic level. First, the reaction of financial markets to the success of most of the countries selected to host the Games was negligible. Second, on an economic level, GDP per capita growth will not accelerate because of the Olympics. The result enriches the academic circle.