Cities are important carriers of regional development, which can play a leading role in regional coordinated development, and the study of urban development level can better grasp the essence and direction of regional development. Based on the traditional gravitational model, a gravitational model was constructed to measure the gravitational strength between cities and the relative gravitational strength of a single city in Gansu Province in 2012 and 2022 with the help of relevant data of population, economy, society, ecology and transportation in 14 cities in Gansu Province, and the evolution of urban spatial gravitational network structure was analyzed. Based on the regional strategy of “one core and three belts” in Gansu Province, the study concludes that the core position of gravitational strength in Lanzhou is significant, and it has a driving effect on the surrounding cities. The Jiuquan-Jiayuguan area has become the sub-center of gravitational intensity, which has not had an obvious driving effect on the surrounding cities. There are significant differences in gravitational values among cities in different regions of the province. The gravitational network structure of urban space has gradually evolved from irregular to “pendulum-shaped” structure. The development of each city should formulate development strategies according to the actual situation of inter-city gravity and urban quality, so as to solve the current situation of backward development of the economic belt of the Hexi Corridor and the ecological function belt of the upper reaches of the Yellow River.