Abstract:With the strategic deployment of "Digital China" in the 14th Five-Year Plan, the digital transformation of China''s major cities is developing rapidly, but how to measure the quality of development in the process of digital transformation is an important issue for governments at all levels. Changes in electricity demand have long been the wind vane and barometer of China''s economic and social operation. Starting from electricity big data, this paper focuses on the connotation of China''s digital development, and constructs a city digital development index system from the three dimensions of resource agglomeration, development activity, and future plasticity, and carries out index calculation based on the data of more than 32,000 key enterprises in Shanghai and Shanghai''s digital infrastructure, and discusses the following issues power data''s ability to analyse and monitor under the digital economy.