A radiator module system for automatic test equipment, including a test arm and a closed-loop circulating cooling device disposed on the test arm. The test arm includes a test head, and an internal channel is formed within and passing through the test head. The closed-loop circulating cooling device includes an inlet and an outlet, respectively connected to the internal channel; a conduit connecting the inlet and the outlet, such that the conduit and the internal channel form a closed-loop circulating channel in which a working fluid flows; a cooling device in contact with the conduit, configured to perform heat dissipation to the working fluid flowing within the conduit; and a driving source configured to drive the working fluid to flow within the closed-loop circulating channel. The working fluid is driven by the driving source to flow within the closed-loop circulating channel to perform heat dissipation.