This paper deeply discusses the basic law of tourist population flow and its influence on the development of tourism market in Heilongjiang Province. Under the background of the vigorous development of global tourism, the flow of tourist population, as the core element of tourism activities, has an important impact on the prosperity and sustainable development of regional tourism market, such as seasonal, spatial distribution and interactive effects. Through the detailed analysis of Heilongjiang tourism market, this paper reveals the market size, resource characteristics, challenges and problems of this market under the action of tourist population flow. Further, this paper analyzes the dual impact of tourist population flow on Heilongjiang tourism market, including the positive effect of promoting local economy, cultural exchange and industrial development, and the negative effect of environmental pressure, over-exploitation of resources and decline of service quality. At the same time, this paper puts forward some strategic suggestions to promote the sustainable development of Heilongjiang tourism market, including rational planning of tourist population flow, strengthening the protection and development of tourism resources, promoting the development of smart tourism, and strengthening regional cooperation and linkage. These suggestions are intended to provide theoretical basis and practical guidance for the scientific planning and management of Heilongjiang's tourism market, and help it achieve long-term prosperity and sustainable development.