Provided are a data transmission method and apparatus, and a device and a medium. The data transmission method comprises: receiving a data packet to be transmitted, wherein said data packet comprises data to be transmitted and chip identification information; determining, from among a plurality of first PCIE physical layer ports, a target first PCIE physical layer port corresponding to the chip identification information, wherein the plurality of first PCIE physical layer ports are interconnected to a plurality of chips in one-to-one correspondence; distributing said data packet to the target first PCIE physical layer port; and sending said data packet to a receiving chip by means of the target first PCIE physical layer port, wherein the receiving chip is a chip that is interconnected to the target first PCIE physical layer port.