A server system is disclosed herein, which comprises a first BIOS (Basic Input/Output System chip, a second BIOS chip, a baseboard management controller (BMC) and a platform controller. In a preset mode, the platform controller is conductively connected with the first BIOS chip through the BMC and the multiplexer so that the server system is activated by the first BIOS chip. Upon detecting a failure of a POST (Power-on self-test) initialization of the first BIOS chip, the BMC transmits a control command to the multiplexer so as to make the platform controller conductively connecting with the second BIOS chip through the BMC and the multiplexer so that the server system is activated by the second BIOS chip.