The integration of culture and tourism has become an important factor in the development of the cultural tourism industry, and a quantitative measure of the degree of integration is important for understanding and promoting the high-quality development of the global cultural tourism industry. This study aims to put forward a comprehensive analysis model to show the development trend of cultural and tourism integration, measure the degree of cultural and tourism integration, and analyze the factors affecting the regional heterogeneity of cultural and tourism integration. Using the spatial quantification method of entropy, the spatial coupling coordination degree model, and the geographical weighting model, this paper analyzes the effect and influencing factors of cultural and tourism integration in various districts and counties in Beijing. The results show that the cultural tourism resource endowment of Beijing presents an upward trend and a gradual spillover trend, with obvious spillover to the east and north. The effect of district integration in Beijing has gradually weakened from the city center to the outside, but there is still a serious phenomenon of two levels of differentiation. Factors such as the economic development level, tourism output, cultural output, policy support, and consumption level have spatial heterogeneity on the effect of cultural and tourism integration in each district of Beijing, but the degree of influence is small.