A server system, a server device, and a power supply recovery method therefor are provided. The server system includes a plurality of servers and a power controller. Each of the servers includes an AC power supply and a DC power supply. The DC power supplies of the servers are mutually connected through a cable. The power controller communicates with the servers. When a specific server detects that the AC power supply belonging thereto does not operate normally, the power controller informs other servers of a power required by the specific server, and the specific server controls the DC power supply belonging thereto to obtain powers provided from other servers through the cable, so as to maintain the operation of the specific server.