The present study aimed to quantitatively evaluate the ecological effects of artificial reefs from the perspective of the food-web structure and provide reference material for marine ecological restoration and conservation research. A stable isotope technique was applied to analyze consumers and their potential carbon sources. Samples were collected from the reef areas built in 2010, 2012, and 2014 and the control area in Dashentang during June 2016. An IsoSource model was used to construct the food web. Stable isotopes were used to calculate the trophic levels of the consumers. The results showed that food sources can be categorized into three categories based on the δ13C values of phytoplankton, particulate organic matter, and soil organic matter. Phytoplankton represented the largest source of carbon for consumers (67.2%~81.5%). The findings from the IsoSource mix model revealed that phytoplankton were the main contributors to the food web in the studied areas. There were no significant differences in the δ13C or δ15N values of the same food sources from different areas. The δ13C values of suspension- feeding bivalves, including Arca subcrenata, Ruditapes philippinarum, and Crassostrea gigas, were significantly higher in the reef areas than in the control area. The proportion of phytoplankton in the carbon sources for suspension-feeding bivalves was significantly higher in the reef areas than in the control area. The δ15N values of consumer species ranged from 7.70‰ to 14.34‰, and the trophic levels ranged from 2.0 to 3.95. The δ15N values or trophic levels of piscivorous consumers were higher in the reef areas than in the control area, and the level of significance increased with the duration of the reefs. The findings indicate that artificial reefs might induce an abundance of organisms in reef areas, leading to changes in the composition of the food sources of suspension-feeding bivalves and an increase in the trophic levels of piscivorous consumers.