A portable exercise device provided includes: a base disc, two pulley assemblies, a support plate, and a fan wheel assembly. A support plate is disposed on the base disc, the two pulley assemblies are provided on the base disc, and the fan wheel assembly is provided on the support plate, so that the fan wheel assembly and the two pulley assemblies are vertically arranged on top of each other, thereby reducing the overall volume. More preferably, because the volume is reduced, the user can arbitrarily move and hang the portable exercise device at the desired position, and because the portable exercise device of the invention can be hung at different positions, which allows the user to train different muscles according to the different positions.