The development of tourism has gradually strengthened its correlation and driving effect on the national economy. Tourism is an important part of the service industry, and the increase of its share means the growth of non-essential consumption, which provides a strong market driver for China's overall economic development. The government emphasizes the driving effect of tourism on economic development. According to the 13th Five-Year Plan (2016-2020) for tourism development, tourism should be developed as an important force in economic transformation. Based on the panel data of 283 prefecture-level cities in China from 2002 to 2016, this study adopts DEA model to measure the comprehensive efficiency, technical efficiency, and scale efficiency of each prefecture-level city. It then establishes spatial-econometric models to investigate the impacts of tourism development on comprehensive efficiency of economy. The main findings are as follows: (1) Overall, the comprehensive efficiency of the sample cities shows a tendency of rising first and then falling, and input-output efficiency is at a low level. Only a few cities achieve the optimal efficiency. The comprehensive efficiency is roughly equivalent in the eastern and central regions, while that of the western region is relatively low. (2) Tourism development can significantly improve the comprehensive efficiency of the cities, which is reflected in the positive change of 0.064% for every 1% increase in tourism revenue. And its effect on the overall efficiency of the economy is significantly higher than that of human capital, proportion of output value of secondary production, number of employees in secondary and tertiary industries, and proportion of government fiscal expenditure. (3) There are regional differences of tourism in improving comprehensive efficiency in China. The effect of tourism development on comprehensive efficiency in the western region is larger than that in the eastern and central regions. This can be attributed to the different development stages of different regions in China. The western region is at the stage of increasing returns to scale, while northeast and central regions, especially their large cities, have entered the mature stage of development, featuring constant marginal returns or decreasing marginal returns.