A server system having optimized cooling, and an installation method. The system comprises a server node, a power supply module, a power distribution board, and a hard disk backplane. A fan is provided between the server node and the hard disk backplane. The power supply module is connected to the power distribution board via a cable to supply power to the hard disk backplane. A hard disk module is installed on another side of the hard disk backplane. The hard disk module is connected to the hard disk backplane via a cable. The server node is connected to the hard disk backplane via a side plate of the node. The fan is connected to the hard disk backplane via a cable. An optimized cooling channel is formed during operation of the fan, and comprises a cool airflow sequentially traveling from the hard disk module to the hard disk backplane, before being drawn by the fan to the server node and then discharged afterwards. The present invention integrates power supply and signal interconnection functions into the hard disk backplane, so as to improve the structure of the airflow channel and the performance of the server, thus enhancing operational stability of the server system.