The drag of coaxial helicopter hub accounts for more than 50% of the total helicopter’s waste drag. It is necessary to research drag characteristics and reduction design of the hub. Wind tunnel test is carried out on a coaxial helicopter hub model, drag reduction scheme and drag reduction scheme with vortex generator. The drag characteristics of coaxial helicopter hub is researched. The drag reduction effect of the drag reduction scheme and drag reduction scheme with vortex generator is verified. The results show that the azimuth, rotation speed and attack angle have little influence on the drag of hub and tis drag reduction scheme. The drag reduction scheme can reduce drag by about 30%, and the drag effect of the vortex generator is not obvious.