A GPU Box server cascade communication method, device, and system. The method includes: detecting an i2c communication bus through a baseboard management controller (BMC) in a powered-up GPU Box server to determine whether a next-stage GPU Box server corresponding to the GPU Box server exists, and if yes, reading an IP address and location information of the next-stage GPU Box server from the i2c communication bus by means of the BMC in the GPU Box server; and storing the IP address and the location information of the next-stage GPU Box server into a data structure of the GPU Box server so that a master control server reads the data structure of the GPU Box server, and establishing network communication with the next-stage GPU Box server according to the IP address and the location information stored in the data structure.