Abstract: In order to improve the mixing performance of the spiral belt stirrer, the eccentric and counter-centred spiral belt stirrers were designed based on the homogeneous experimental design method. And the mixing time, mixing effect, power and mixing energy per unit volume of the optimal solution were compared with the original solution by numerical simulation. The results show that the mixing time of the eccentric spiral stirrer is 1.25-17.5 min lower than that of the counter-centre type, but the mixing effect is 2.1%-9.1% lower; and the power consumption of the counter-centred spiral stirrer is 0.02-0.53 kW higher than that of the eccentric type, and the mixing energy per unit volume is 120-931 kJ/m³ higher. The optimum solution is the counter-centred spiral mixer with 5 spiral belts, 1200 mm pitch and 35 rad/min. The mixing effect is improved by 8.5% compared to the original solution, the mixing time is reduced by 20 min, the power consumption is increased by 4.43 kW and the mixing energy per unit volume is reduced by 54.09 kJ/m³.