The invention discloses a microminiature personal combined navigation system as well as a navigating and positioning method thereof. The system is composed of a subsystem installed on the foot part of a human body and a subsystem installed on the trunk position, wherein the subsystem installed on the foot part comprises an MEMS IMU (Micro-electromechanical Systems Inertial Measurement Unit), a magnetometer and a communication module; and the subsystem installed on the trunk position comprises a satellite navigation receiver, a Doppler velometer, an atmospheric pressure altimeter, a communication module and a microminiature navigation computer. The positioning method comprises the following steps of: collecting the MEMS IMU signal; modeling and correcting the random error of a gyroscope and an accelerometer; initially aligning an MEMS inertial navigation system; resolving strapdown inertial navigation, and correcting zero speed; carrying out combined navigation of the MEMS inertial navigation system/ satellite navigation receiver/ the Doppler velometer/ the magnetometer/ and the atmospheric pressure altimeter; and displaying the navigation result in real time. The microminiature individual combined navigation system is convenient to individually carry, individual real-time gesture fixing, velocity measurement and positioning can be realized, and whole and precise real-time navigation positioning information can be provided for pedestrians, operating personnel, soldiers, rescue workers and the like in the complex electromagnetic environment.