Based on the assumption of constant temperature and no nutrient salt limitation, a mathematical model coupling sinking algae growth and water environment of Lake Taihu was used to investigate the effect between the vertical turbulent diffusion and background diffused attenuation coefficient(K_bg) on the growth of sinking algae. The simulation results showed that the total biomass growth of the sinking algae could be sustained without vertical turbulent diffusion in the relatively clean water (K_bg was less than 1.1/m); in turbid water (K_bg was between 1.1~3.0/m), the growth required vertical turbulent diffusion to maintain, and the minimum vertical turbulence diffusion increased with the K_bg. The Peclet number between the minimum vertical turbulence diffusion(D), water depth(z) and the algae sinking speed(v) should between 0.38~13.89, otherwise the minimum vertical turbulence would have little effect on the growth than other factors (for example, algae sinking speed or light attenuation). When the K_bg was greater than 3.0/m, the light intensity of the water column was too low to maintain the total biomass growth of algae. This paper helped to clarify the phytoplankton population succession mechanism in aquatic ecosystems under climate change.