The invention provides a handheld dust collector which comprises a sucking-in pipeline, an air flow generator component, a cyclone separator component, a filter component, a power supply component and a handle. The sucking-in pipeline has a longitudinal axis. The air flow generator component generates air flow which flows along the sucking-in pipeline. The cyclone separator component is communicated with the sucking-in pipeline and is used for separating dust which is sucked in from air flow. The filter component is arranged in the handheld dust collector. The power supply component provides power for the air flow generator component. The handle is used for a user to hold. The air flow generator component and the cyclone separator component are arrayed in the direction perpendicular to the longitudinal axis. Compared with the prior art, an air flow generator and a cyclone separator are arranged up and down, so that whole arrangement is small, exquisite and compact, the air flow generator and the cyclone separator are directly communicated, and accordingly the sucking force of the dust collector is strong.