A virtual data center (VDC) resource mapping method and device. The method includes: a) receiving a VDC resource request, where the VDC resource request carries a virtual machine distribution identifier, and the virtual machine distribution identifier is used to indicate a maximum quantity K of virtual machines that can be borne by a single physical server; b) selecting, from an unmapped virtual machine set Q in the VDC resource request, M virtual machines to form a partition P; c) selecting a target physical server that can provide a physical resource required by the partition P, and mapping the partition P to the target physical server; and d) removing, from the set Q, the M virtual machines on which resource mapping has been performed, and repeatedly performing steps b), c), and d) until no virtual machine on which resource mapping has not been performed exists in the set Q.