The invention discloses a radiator for an electrical device box. The radiator comprises a hollow shaft motor, a control system controlling the hollow shaft motor to operate, a hollow fan, a fairing and a fixing rack, wherein the hollow fan, the fairing and the fixing rack are arranged on the hollow shaft motor, a through hole is axially formed in the middle of a rotor of the hollow shaft motor, the hollow fan is arranged at the output end of the rotor, and a horizontal cable channel for a cable to pass through is formed at the central position of the hollow fan and is communicated with the through hole formed in the rotor. The fairing covers the outer side of the hollow fan and is provided with an air inlet and an air outlet, the air outlet corresponds to the horizontal cable channel on the hollow fan and is not smaller than the through hole formed in the rotor in diameter. The radiator can be installed in a cable inlet for pre-cutting of the electrical device box and can make the cable normally pass through, can also effectively prevent bugs, rats, birds and other animals from entering the electrical device box and damaging the electrical device box while cooling the air in the electrical device box.