To understand the changes and influencing factors of the periphyton ecological stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) in the wetland, we analyzed the ecological stoichiometry of C, N, and P in two growth stages (periphyton growth period and periphyton decline period) in four different habitats (lakeside zone, artificial wetland, farmland ditch, and sewage treatment plant) of Caohai Wetland in Guizhou Province. The results show that the trophic level index was in the order of sewage treatment plant (51.55±4.50)> farmland ditches (50.41±4.50)> constructed wetland (47.20±6.72)> lakeside zone (41.86±6.91), and the water quality from upstream to downstream show a trend of gradual improvement. Interestingly, the contents of C, N, and P in periphyton increased with increasing water nutrient concentration, while the periphyton stoichiometric ratio shows a decreasing trend. The contents of C, N, P and C：N of periphyton in the growing period were lower than those in the decline period in the same habitat but the contents of N：P and C：P were opposite. The elements of N and P in the growth period of the periphyton are weakly stable (H_N=2.358, H_P=2.576), and the aging stage is the steady-state type (H_N=10.99, H_P=5.78). On the whole, the N：P of periphyton in the two growth stages is in steady-state (H_N：P=4.504). According to the measurement ratio of the optimal growth rate of the periphyton, the lakeside zone is in the P-restricted state, while the constructed wetlands, sewage treatment plants, and farmland ditches are not subject to nutrient restrictions. Correlation analysis shows that the content of N, P, and the stoichiometric ratio of periphyton are significantly affected by the level of water nutrition, especially total phosphorus (TP) and total nitrogen (TN) concentrations. Non-linear surface fitting analysis shows that N：P of periphyton is mainly affected by the changes of TP concentration, while C：N is mainly affected by TN concentration, and TN and TP concentrations are equally important to C：P. This study shows that the three-dimensional model based on the TP and TN concentrations of water, and the stoichiometric ratio of periphyton can be used to evaluate the relationship between the trophic level of the water and the stoichiometry of periphyton.