The Jinhewan Wetland is located in northeastern China, and plays an important role in protecting the biodiversity and regulating the microclimate in Harbin City. Although phytoplankton community studies on wetlands from northern China have increased recently, studies of the phytoplankton community in the Jinhewan Wetland are limited. To better understand processes of phytoplankton community succession in relation to environmental parameters, a detailed survey of phytoplankton functional groups in spring, summer, and autumn are necessary. Therefore, we studied the phytoplankton functional groups and 10 environmental parameters during spring (May), summer (August), and autumn (July). The aim of this study was to understand the succession process of phytoplankton functional groups between seasons, and furthermore explore the dynamic parameters in the Jinhewan Wetland. In this study, phytoplankton were qualitatively and quantitatively collected from 12 sampling sites in four typical habitats. A total of 376 phytoplankton species were identified, belonging to 8 families, 10 classes, 19 orders, 19 families, and 101 genera. The phytoplankton species composition was dominated by Bacillariophyta (39.62%) and Chlorophyta (35.64%), followed by Euglenophyta (10.11%) and Cyanobacteria (9.84%), and the proportions of Pyrrophyta, Cryptophyta, Chrysophyta, and Xanthophyceae were relatively low. Our study showed that the average abundance of phytoplankton in the Jinhewan Wetland was significantly different (P < 0.05). The average abundance in summer was the highest (12.90×10⁶ ind/L), followed by autumn (5.95×10⁶ ind/L), and spring (2.55×10⁶ ind/L). The range of change was 0.97-14.83×106 ind/L, ranging between 0.47-30.17×10⁶, 5.95×10⁶, and 2.55×10⁶ ind/L, respectively. We arranged phytoplankton taxa data from spring, summer, and autumn into 20 functional groups. Groups B/D/F/H1/J/MP/S2/X1 were predominant in spring, groups B/D/H1/Lo/S1/S2/SN/MP/Y were predominant in summer, and groups B/D/F/H1/J/MP/S2/X1 were predominant in autumn. A two-way ANOVA and single-factor cross-similarity test (one-way ANOSIM) showed that there were significant differences in representative functional groups between spring, summer, and autumn (P < 0.05), the representative functional group succession was obvious (P < 0.05), and functional group assemblages were significantly different (P < 0.01). In addition, a SIMPER analysis indicated that the primary contributing phytoplankton functional groups were S2/H1/B/D/Lo/X1/MP in the Jinhewan Wetland. A Canonical Correspondence Analysis (CCA) based on representative functional groups of 10 environmental variables revealed that total nitrogen (TN) was the primary factor affecting the phytoplankton functional group succession in this wetland, and conductivity (SpCond) and pH were closely related to phytoplankton functional group distribution.