As a "New Blue Ocean" for urban consumption to increase employment， boost consumption and drive regional development， the night economy has gradually become a research hotspot in the "Post-Pandemic era". The “nighttime economic agglomeration center” is the core and foundation of the nighttime economic development， and there is no systematic studies available at home and abroad. As a social economic element， it has the characteristics of non-uniform symmetry and "grey clustering"， so it cannot simply apply the traditional geographical clustering center identification method. Based on the theory of "point-axis system"， this paper proposes a method to identify and extract the nighttime economic agglomeration centers， and uses the Geo-information Tupu of generalized symmetric to deconstruct the spatial pattern and differentiation mechanism of the nighttime economic agglomeration centers in downtown Shanghai. For the first time， this paper provides a systematic method reference for rapidly and accurately identifying the nighttime economic agglomeration centers and scientifically exploring their spatial distribution characteristics， and provides decision support for promoting the prosperity and sustainable development of nighttime economy. The results show that： within the central city of Shanghai， a total of 12 first-class nighttime economic agglomeration centers and 26 second-class nighttime economic agglomerations were extracted， and the average vitality values of the night-time economy were： 0.49 and 0.24， respectively. Conclusions （1） The method proposed in this paper can quickly identify and extract nighttime economic agglomeration centers； （2） The Shanghai nighttime economic agglomeration centers present a "center-periphery" spatial distribution pattern， forming a distinct hierarchical system； （3） The degree of infrastructure perfection and the distance from the city center are the main driving factors for the differentiation of Shanghai nighttime economic agglomeration； （4） The "Color Symmetry" distribution spatial pattern of the agglomeration center indicates that the night economy of Shanghai in a reasonable and sustainable development stage. In the future planning，it can be expanded and filled internally along Metro Line 2. The central connecting line of the agglomeration symmetry can also be used as the development axis to upgrade the nighttime economic agglomeration effect in the form of "Agglomeration Area".