Abstract: As the birthplace of modern urban civilization, traditional small towns, such as historical blocks, traditional buildings, cultural customs, regional characteristics and natural landscapes, are all in urgent need of upgrading and transformation as the problems of urban development become prominent. Therefore, the protection of historical and cultural blocks has gradually received widespread attention from the society, the theoretical methods and technical measures of protection have also gained new understanding and insights along with the progress of times and the continuous practice of protection. This article takes the protection plan for the historical and cultural block of Tunxi Old Street in Huangshan City, Anhui Province as an example. Based on the perspective of "protection", this article focuses on the integration of the technical thinking of municipal engineering planning and traditional block protection planning under the framework of protection planning, and better developing innovative thinking of planning technology for sustainable protection and development of small towns and blocks, realizing a gradual update method.