Based on the nighttime light data and relevant statistical data in Shandong Province from 2015 to 2024, this study integrates spatial pattern analysis and a modified economic gravity model to explore the evolutionary characteristics of the regional economic spatial pattern. The results show that county-level nighttime light presents a gradient distribution of “high in the core, low in the periphery”, with the dual-core high-value areas of Jinan-Qingdao expanding continuously. In spatial distribution, regional economy shows a significant positive spatial correlation, while the degree of agglomeration weakens with fluctuations, reflecting a balancing trend of core radiation and peripheral catch-up. The standard deviational ellipse stretches northeast-southwest with an area expansion of 1.6%, indicating a gradual increase in spatial radiation capacity of the regional economy. The gravity center shifts from west-south to north-west, reflecting spatial expansion and partial adjustment of the economy. The total urban economic gravity has increased substantially, forming a development pattern dominated by Jinan-Qingdao and linked by sub-core circles such as southern Shandong. Radiation corridors of core cities have upgraded from local single points to full coverage, and corridor evolution is closely related to regional strategic development and transportation infrastructure. This study can provide a reference for optimizing the high-quality development strategy of regional economy in Shandong Province.