The present disclosure discloses a direct-current power supply expansion card. This direct-current power supply expansion card comprises a circuit board, an input interface arranged on the circuit board, a direct-current output interface arranged on the circuit board, and a fixing insertion plate connected to the circuit board, the fixing insertion plate being used for fixing the circuit board onto a host case. The technical solution of the direct-current power supply expansion card in the present invention converts, by means of the direct-current power supply expansion card, a power supply of a desktop computer into a direct-current power supply capable of charging a hand-held device, thereby improving the convenience and safety of charging for a user.