The present invention relates to a self-propelled onion harvester with a globular agricultural product selector, in which: a first excavation unit for excavating an onion is installed at the front of a vehicle body driven by self-driving power； and a second collecting conveyor unit inclined to an upper portion of the vehicle body is installed at the rear of the first excavation unit. Therefore, the excavated onion can be transported to the upper portion of the vehicle body and then horizontally transported to the rear side of the vehicle body by a third transport conveyor unit which is horizontally installed in a back-and-forth direction at the upper portion of the vehicle body, such that a stem thereof is cut by a cutting blade of a stem cutting unit in a state in which the stem is vertically positioned by an air blower, and then the onion is delivered to a transport conveyor of a selector at the rear side to be selected. To this end, the present invention comprises: a first excavation unit (100) which is installed at the front side of a vehicle body (10) in order to excavate an onion planted on a farm； a second collecting conveyor unit (200) which collects the onion excavated by the first excavation unit (100) in order to transport the same to an upper portion of the vehicle body (10)； a third transport conveyor unit (300) which horizontally transports the onion (0), which is transported to the upper portion of the vehicle body (10) by the second collecting conveyor unit (200), to the rear side of the vehicle body (10)； a stem cutting unit (400) which is installed in the midst of the third transport conveyor unit (300) in order to cut a phylloclade (P) of the onion which is being transported； a collecting unit (500) which is installed at the rear portion of the vehicle body (10) in order to collect the onion, whose stem is cut while passing through the stem cutting unit (400), in a collecting sack (not shown)； and an air blower (410) which upwardly blows the phyll
