Submerged macrophytes, periphyton and phytoplankton are main primary producers in shallow lakes and their competitive interactions can be affected by increased nitrogen and phosphorus concentrations and low light stress. Exploring how changes in nutrients and light intensity separately/jointly affect these primary producers and their interactions is of great significance for our further understanding of the maintenance mechanisms of stable states in lakes under the context of global climate change. We selected Potamogeton crispus, a dominant species in winter and spring in the Yangtze River basin, as plant material. We conducted an indoor microcosm experiment simulating different conditions of nutrient concentrations (low nutrient: TN 0.8mg/L, TP 0.03mg/L, moderate nutrient: TN 1.8mg/L, TP 0.14mg/L) and shading (30%, 60%, and 100% incident light) to study the effect of light and nutrient supply on different types of aquatic primary producers. The results showed that within the nutrient range that we had set up in the experiment, increased nutrient level promoted the growth of P. crispus, periphyton and phytoplankton, but the positive effect of nutrients on periphyton and phytoplankton was much greater than that on submerged macrophytes. An increase in shading significantly inhibited the growth of P. crispus, but the effect of light on macrophyte growth was only obvious under moderate nutrient, but not under low nutrient. Phytoplankton and periphyton were more responsive to different water nutrient levels than to changes in light intensities. The difference in phytoplankton and periphyton biomass caused by different nutrient concentrations was much greater than that caused by different light intensities, indicating that nutrient was the main factor that limiting phytoplankton and periphyton growth in the present experiment. These results suggested that as eutrophication intensifies, since P. crispus has a poor growth under low light conditions, its inhibitory effect on the algae can be weakened. Consequently, the combined effect of reduced light intensity and increased nutrient concentrations will promote algae growth, which can cause macrophyte decline by shading. In addition, during the process of water eutrophication, environmental changes such as increased inputs of dissolved organic matter, enhanced wind waves and biological disturbances can reduce the light intensity at the lake bottom, which can exacerbate the impact of eutrophication on submerged macrophytes, leading to a negative impact on the maintenance of stable states in lake ecosystems in different seasons.