Artificial reefs are a key tool for the restoration of ecological habitat in marine ranches. The construction of artificial reefs has many ecological effects, such as flow field, shelter, and bait effects. The attached community on artificial reefs are an important factor for the formation of bait effect. To explore the effects of reef age on community structure and functional traits of attached organisms, quadrate sampling was conducted on an artificial reef at Furong Island in Laizhou Bay in the spring, summer, and autumn of 2019. A total of 94 species of attached organisms were collected. Arthropoda had the largest number of species (33), followed by Mollusca, which included 21 species. There were 66 species on short-age (1 a) artificial reef (AR-AB), and 79 species on long-age (4–5 a) artificial reef (AR-CD). There were differences in the species composition and dominant species of attached community for different seasons and reef ages. AR-CD were significantly higher than AR-AB in Margalef species richness, Shannon-Wiener diversity, and Pielou evenness indices. Six functional traits (including feeding habits, mobility, habitat, body size, longevity, and flexibility) were selected to compare the relative abundance of functional traits in different seasons and reef ages. The results showed that the artificial reefs in this area are more likely to be attached by those species with filter-feeder, inactivity, sessile, long-lived (＞ 5 a), and extremely small (＜1 cm) characteristics, but no body flexibility (Membranipora grandicella, for example). The differences in functional traits between AR-AB and AR-CD were reflected in feeding habits, mobility, and habitat. The relative abundance of predator, high mobility, burrower, and crawler characteristics in AR-CD were significantly higher than in AR-AB (P＜0.05). However, the relative abundance of filter-feeder, sessile, and inactivity characteristics in AR-CD were significantly lower than in AR-AB (P＜0.05). The functional diversity index and functional redundancy of the attached community of AR-CD were higher than that of AR-AB, though the differences were non-significant. In this study, traditional biodiversity indices and biological traits were used to analyze the differences in community structure and functional traits of attached organisms between short- and long-aged reefs in different seasons, providing a new perspective on the ecological effects of artificial reefs.