In the process of regional economic development, spatial polarization advances with the development of the spatial economic networks, and multiple growth poles organically combine and coexist with spatial economic networks to form a multi-polar network spatial organization. To implement the development strategy of the Yangtze River Economic Belt, the construction and optimization of the multi-polar network development pattern should be a key point. Based on the analysis framework of “economic network-multiple growth poles-symbiotic relationship”, the spatial economic network of the Yangtze River Economic Belt was constructed by using the headquarters-branch data of A-share listed companies from 2000 to 2017, and its development level was analyzed through node degree, network density, point degree centrality, and network connectivity. According to the comprehensive urban index (the sum of standardized node degree and scale weighted economic growth rate), the range of growth pole and its core cities are determined, and the symbiotic relationship between growth pole and spatial economic network is tested by symbiotic degree model. The results show that: the development level of spatial economic network in the Yangtze River Economic Belt increases steadily and becomes mature, and has formed three growth poles in the Yangtze River Delta, the middle reaches of the Yangtze River and Chengdu-Chongqing; the economic connection between the three growth poles continues to strengthen, among which, the connection intensity between the growth pole in the Yangtze River Delta and the growth pole in the middle reaches of the Yangtze River is the largest, followed by the growth pole in the Yangtze River Delta and the Chengdu-Chongqing growth pole, while the connection intensity between the growth pole in the middle reaches of the Yangtze River and the Chengdu-Chongqing growth pole is small; there is a positive asymmetric reciprocal symbiotic relationship between the growth pole and the space economic network, the promotion of the growth poles to the space economic network is greater than the promotion of the space economic network to the growth poles, the promoting effect of the space economic network on the growth pole is constantly increasing, and the promoting effect of the growth pole on the space economic network shows a trend of weakening at first and then increasing. It can be seen that: a multi-polar network spatial organization has taken shape in the Yangtze River Economic Belt; While further promoting the accelerated development of the three growth poles, we should strengthen the interaction between the growth poles, establish a multi-dimensional and multi-level closer spatial economic connection, improve the modernization level of the spatial economic network, and promote the continuous optimization of the spatial development pattern of the multi-polar network in the Yangtze Economic Belt.