<p>Based on the stochastic collision-coalescence equation for cloud droplets and the definition of the autoconversion rate from cloud droplets to raindrops (ARCR), this study analyzes and derives an ARCR equation from the collision-coalescence process. This equation narrows the integration range of the stochastic collision-coalescence equation, providing a theoretical basis for accurately and efficiently calculating the ARCR. Utilizing the results of the turbulent collision kernel and turbulent collision efficiency, as well as the ARCR equation, an accurate and efficient model for the ARCR was established. Modeling results indicate the following: (1) The ARCR increases with the enhancement of turbulence. The rate of increase was fastest when the turbulent dissipation rate was between 0 and 20 cm² s⁻³, slower when it was between 20 and 50 cm² s⁻³, and intermediate when it was between 50 and 500 cm² s⁻³. (2) Compared to the case without turbulence, the ARCR increased by approximately 20% when the turbulent dissipation rate was 100 cm² s⁻³, and by over 100% when it was 500 cm² s⁻³. Therefore, turbulence has a significant impact on the ARCR only when the turbulent dissipation rate exceeds 100 cm² s⁻³. (3) The influence of turbulence on ARCR results increases with an increase in cloud water content. When there was no turbulence and the cloud water content exceeded 0.68 g m⁻³, a strong linear relationship existed between cloud water content and the ARCR. (4) The effect of turbulence on the ARCR results decreases rapidly with an increase in the cloud droplet number concentration. (5) The impact of turbulence on the ARCR becomes stronger with a decrease in the shape parameter, which corresponds to the increase in the relative dispersion of the cloud droplet spectrum (i.e., as the cloud droplet spectrum broadens).</p>