An optical system with optical image stabilization of the present invention comprises at least one movement determination unit determining a movement of the optical system, a control circuitry generating a movement compensation signal using the movement information of the optical system from the movement determination unit, and a Micro-Electro Mechanical System (MEMS) unit made by microfabrication technology and controlled by the control circuitry with the movement compensation signal 32C to stabilize an image of an object formed on the image plane. The MEMS unit comprises a substrate, an MEMS mirror movably connected to the substrate and configured to have a motion comprising a rotation, and at least one actuation unit configured to actuating the MEMS mirror. The actuation unit comprises a micro-actuator disposed on the substrate, communicatively coupled to the control circuitry, and configured to have in-plane translation in accordance with the movement compensation signal and a micro-converter having a primary end rotatably connected to the micro-actuator. The micro-actuator with the in-plane translation exerts a force on the primary end of the micro-converter and the micro-converter delivers the force to the MEMS mirror to make the MEMS mirror have a required rotation. The optical system with optical image stabilization of the present invention provides fast speed, light weight, simple operation, and high image quality image stabilization for the optical system.