Abstract: The viscosity of high entropy alloy liquid atomization process has important influence on atomization effect, but the study on the viscosity of high entropy alloy liquid is less. In this paper, using the existing ternary alloy viscosity model, a new viscosity model of CoCrFeMnNi high-entropy alloy melt with equal molar ratio was established through model expansion. The influence of temperature on the viscosity of five-element high entropy alloy was studied. The viscosity curve was drawn and modified, and the relationship between temperature and the viscosity of high entropy alloy was calculated. The model study shows that the viscosity decreases from 0.0211 Pa·s to 0.0114 Pa·s when the temperature increases from 1360 K to 2000 K. With the increase of the content of five metals, the viscosity of the high entropy alloy increases. Cr metal has the most significant effect on the viscosity of the alloy, while Fe and Co have the same effect on the viscosity. The results of the prediction model of liquid viscosity of five-element high entropy alloy are consistent with the experimental results of thermal state experiment, which has a guiding significance for the regulation of melt viscosity during the atomization process of high entropy alloy.