Abstract: Disclosed is a fast and automatic deployment method for a cluster system by using a ramdisk. A master node is provided for sending a kernel and a system image file after pre-booting at least one worker node in a cluster system via a network. The worker node claims segments of installed RAM to form a ramdisk and buffer the system image file, and after the kernel is executed to install the system image file, a register signal is sent to the master node to request a configuration profile, and related service setup and OS installation are completed by self-setting. Therefore, the fast reading property of the RAM expedites the effect of building and automatically deploying the entire cluster system to simplify the construction complexity and maintenance effort and operation costs.