Abstract: Periphytic algae, as crucial aquatic organisms, have their community characteristics such as species composition, dominant species, density, and biodiversity indices widely utilized for monitoring and assessing the stability and health of aquatic ecosystems. Based on investigation data of periphytic algae and water environmental parameters from 16 sampling sites along the Tianjin section of the Beijing-Hangzhou Grand Canal during spring (May), summer (July), and autumn (September) 2023, this study employed Canonical Correspondence Analysis (CCA) to explore the relationships between periphytic algal community characteristics and environmental factors, as well as their spatial distribution patterns. The results revealed that 70 species belonging to 7 phyla were identified, with Chlorophyta and Cyanophyta predominating (50 species), followed by Bacillariophyta (15 species). Cyclotella meneghiniana and Fragilaria capucina from Bacillariophyta were identified as dominant species across all three seasons. The algal density peaked in spring (2.87×10⁴ cells/cm²) and reached its lowest value in autumn (1.41×10⁴ cells/cm²). Water quality assessments indicated light pollution levels during all seasons and on average, while the Shannon-Wiener diversity index and Pielou evenness index suggested good ecological conditions throughout the study period. CCA analysis demonstrated that water temperature, total nitrogen (TN), electrical conductivity (COND), and dissolved oxygen (DO) were the primary environmental factors influencing spatial-temporal variations of dominant periphytic algal species.