A foldable dust collector of the present invention includes a supporting portion, a case and an air pump. The supporting portion is foldable. The case is disposed on the supporting portion. The case is pivotable with respect to the supporting portion. The air pump is disposed on the case. The air pump is used for drawing air into the case.Therefore, the foldable dust collector of the present invention can be transformed. A width of the foldable dust collector is changeable. As such, the foldable dust collector is easier to be stored or be transported. Moreover, the foldable dust collector can be used in a small space.