With the continuous advancement of the Belt and Road Initiative, countries along the Belt and Road are becoming the most important geo-economic space for China’s peaceful rise. This paper constructs a geo-economic model to measure the geo-economic relations between China and countries along the Belt and Road, analyzes the spatial-temporal patterns of geo-economic flow between China and these countries, and discusses the spatial agglomeration of geo-economic flow between China and these countries. The results show that the geo-economic flow between China and the countries along the Belt and Road is increasing and the geo-economic relations between China and these countries are continuing to improve. Trade flow is far greater than investment flow, and China’s geo-economic relations with these countries have mainly relied on trade flow. The spatial differentiation of geo-economic flow between China and countries along the Belt and Road is significant. The development of geo-economic relations is unbalanced, and regional powers play an important role. The geo-economic center of gravity of China and countries along the Belt and Road was moving in the northeastern part of India and it first moved to the northwest and then to the southeast. China’s geo-economic space has obvious core-peripheral structure characteristics, and Southeast Asia is the core area of China’s geo-economic space. China’s geo-economic space presents a northwest-southeast pattern in the direction. There has been a significant, positive spatial autocorrelation in geo-economic flow between China and the countries along the Belt and Road, but the overall spatial agglomeration has been weak. The geo-economic flow agglomerations of China and these countries have mainly occurred in Southeast Asia, and the main agglomeration type has been high–high. The geo-economic activities of China and Southeast Asia had certain spatial spillover effects. To promote the sustainable development of China’s geo-economic relations with the countries along the Belt and Road, China should upgrade investment networks with these countries, optimize geo-economic relations with regional powers, and promote the full development of trade flow, investment flow and other geo-economic element flow.