The present disclosure relates to a method and a device for cross-card link aggregation of virtual function ports of DPUs, and a medium. The method includes: providing a plurality of data processing units, each of which is communicatively connected to a virtual machine and a switch respectively, performing link negotiation for the virtual machine and the switch respectively, acquiring a to-be-communicated data message, further determining a communication link for the to-be-communicated data message, where the communication link is a message channel between a virtual function port in the virtual machine, a virtual function port representor corresponding to the virtual function port in the virtual machine, an uplink corresponding to a physical port in the data processing unit, the physical port in the data processing unit, and the switch; and performing communication for the to-be-communicated data message based on the communication link.