Short-circuit flow rate is a crucial indicator in assessing the separation performance of cyclone separators. The existing literature lacks a comprehensive exploration of how both structural and operating parameters affect this rate. Previous studies produced inconsistent conclusions, and a calculation formula for short-circuit flow rate is absent. Therefore, this paper proposes a novel method for calculating short-circuit flow rate and analyzes it within cyclone separators under different inlet area coefficients KA, dimensionless vortex finder diameters Der, and inlet velocities Vi using response surface methodology. The findings reveal a significant negative correlation between short-circuit flow rate and KA, while positive correlations with Der and Vi are observed. The calculation formula is derived using response surface methodology. The paper concludes by analyzing the influence mechanisms of KA, Der, and Vi on short-circuit flow rate in the separator, aiming to provide valuable insights for the structural optimization of cyclones in engineering applications.