The development efficiency of tourism is an important indicator of the input-output status of tourism in a region. This study used the data envelopment analysis (DEA) model and data from 329 prefectural-level administrative regions of China to comprehensively measure the development efficiency of tourism in 2018. Spatial autocorrelation, Getis-Ord Gi*, and geographical detector were used to explore the spatial pattern and influencing factors of tourism development efficiency. The main conclusions include: (1) Areas with high level, medium-high level, medium level, medium-low level, and low level of comprehensive tourism development efficiency accounted for 16.11%, 17.93%, 27.96%, 26.75%, and 11.25% of the evaluated administrative units respectively. There were clear regional differences in pure technical efficiency, and the high level areas were mainly distributed in the junction of the terrain ladders, the Yangtze River Delta city group, and the Pearl River Delta city group. In terms of scale efficiency, the division was roughly along the “Hu Line”, higher in the southeast and lower in the northwest. (2) The efficiency of tourism development showed spatial autocorrelation, characterized by “large agglomeration and small dispersion” on the whole. Cold and hot spots showed obvious spatial clustering characteristics hot in the south and cold in the north with southwest, South, and East China showing high value clustering, and North, Northeast, and northwest China showing low value clustering. According to the development level and spatial characteristics, tourism development efficiency can be divided into four types: radiation-driven, edge-dependent, overall promotion, and optimized promotion. (3) The efficiency of tourism development is affected by multiple factors, among which tourism service level, tourism development quality, and tourism resource endowments are the leading factors for the spatial differentiation of tourism development efficiency. Promoting tourism development and improving tourism service level and tourism resource use conversion rate are important ways to improve the efficiency of tourism development. By analyzing the spatial pattern and influencing factors of the tourism development efficiency of Chinese prefectural-level administrative units, we hoped to provide a decision-making basis and theoretical support for exploring the effective ways of improving the quality and efficiency of tourism, transforming and upgrading the tourism industry, and increasing the investment and utilization level of tourism development resources.