The theory of urban catalyst is to promote the maturity of the objective conditions of urban construction, through the intervention of new catalyst elements, triggering a certain "chain reaction", so as to promote the sustainable and progressive development of the city according to the will of the inhabitants. By means of actual research and questionnaire survey, we integrate and sort out the current situation of historical and cultural neighborhoods, existing historical sites, traditional culture, etc., and explore the applicability of its operational characteristics under the special environment of historical and cultural neighborhoods by combining with the "urban catalyst theory", through repairing and renewing the historical buildings, old residences, cultural heritage, etc. of Shantang Street of Suzhou. By repairing and renewing the historical buildings, old houses and cultural heritage of Shantang Street in Suzhou City, it protects and develops the traditional culture of Shantang Street in the form of point leading to line and line leading to surface in the backdrop of the historical and cultural district as well as the needs of the old community, and drives the development of the whole district in a small-scale and gradual way to provide a new way of thinking for the renewal of historical and cultural districts.