Abstract Located in the Lushunkou District of Dalian, Liaoning Province, the Taiyanggou Historic District is one of the most well-preserved modern historic districts in China, with the most surviving historic heritages. The area is home to a large number of cultural heritages, ranging from national to district level, as well as a large number of modern historic buildings that are not on the conservation list, which have immeasurable historical and cultural value. This District is reputed as an “open-air architectural exposition”. However, as Lushun is a military port city, most of the area is under the jurisdiction of the army, and the government and the army have multiple administrations that do not form a unified combination, making it difficult to implement conservation and development in the Taiyanggou Historic District. Eventually, this leads to problems of stagnant development, environmental degradation, population loss, population aging and a gradual decline in the vitality of the district. Therefore, how to reshape the vitality of the district and promote its long-term development while preserving its original historical appearance to the greatest extent has become an urgent problem to be solved. The paper began with an in-depth interpretation of the connotation of “vitality” and “vitality improvement” in historic districts through previous studies. The five major components of the vitality of historic districts were summarized as physical space vitality, social vitality, cultural vitality, economic vitality and political vitality. Subsequently, from these five aspects, the elements of vitality of the Taiyanggou Historic District were extracted and summarized, and the problems of its current decline in vitality were analyzed. Finally, using the problem-oriented and goal-oriented research ideas, a targeted approach was adopted to explore strategies to improve the vitality and get out of its current development dilemma, with a view to shedding light on the conservation and renewal of Taiyanggou Historic District.