A graphics card heat-dissipating device includes: a main body, a support seat, and a fixed element. The main body has a first heat-dissipating portion and a second heat-dissipating portion, and the first heat-dissipating portion has a first opening and the second heat-dissipating portion has a second opening. The support seat is used for supporting a chip, and the support seat has a third opening. The fixed element is fixed on the first heat-dissipating portion by passing through the second opening, the third opening and the first opening in sequence for attaching the chip on the first heat-dissipating portion. Therefore, the heat convection function and the heat-dissipating efficiency are increased.