The invention discloses a fan-out multi-device hybrid integrated flexible micro-system and an associated fabrication method in the field of microelectronics. The flexible microsystem uses microelectromechanical system (MEMS) chips and/or integrated circuit (IC) chips as the device units, flexible isolation trenches filled with flexible polymer as a flexible connection between the device units, and metal wiring layers to provide electrical interconnections between the device units. The disclosed multi-device hybrid integrated flexible micro-system completed by a fan-out method not only retains excellent electrical performance of silicon-based devices, but also realizes flexibility of the overall micro-system, and has stable structure and reliable performance.