A hydrocyclone quench box was designed according to the fluid dynamics of spiral flow.The quench box size, the drainage tube diameter, and the inlet tube diameter were designed based on Froude number and conservation of mechanical energy.The pressure drop of the hydrocyclone quench box was measured, and the liquid volumetric mass transfer coefficient was determined by oxygen absorption.The hydrocyclone quench box was compared with the horizontal flow quench box.The streamline of hydrocyclone quench box was simulated by computational fluid dynamics software.It was found that the pressure-drop and liquid volumetric mass transfer coefficient of the hydrocyclone quench box was better than the horizontal flow quench box .The pressure drop was less than 20 kPa and the liquid volumetric mass transfer coefficient was 0.0256 s -1 at 10 m 3·h -1 liquid flow rate and 60 m 3·h -1 gas flow rate.Simulation indicated that the average length of streamline under spiralling was 4 times of that under non-spiralling condition, which enhanced mixing for gas and liquid.