A multi-mode screensaver for embedded system is designed to realize autonomous power management and improve utilization of system resource. Application of a three-mode screensaver, including Black Screen (Mode_B), Photo Slide (Mode_P) and Clock Display (Mode_C), has been validated on a multimedia platform based on μC/OS-II embedded system. During its engineering implementation, optimizations on code execution efficiency and memory space allocation are taken into account. The screensaver is designed to be configurable according to individual needs. The validation result demonstrates that the software-only multi-mode screensaver can be applied in practical products of embedded system in our daily life to bring in actual benefits.