Micro-strapdown altitude heading reference system and working method thereof

The invention relates to a micro-strapdown altitude heading reference system and a working method of the micro-strapdown altitude heading reference system. The system comprises a data acquisition module, a data processing resolving module and a peripheral communication interface module, wherein the data acquisition module integrates a three-axis gyroscope, a three-axis accelerometer, a three-axis magnetic resistance sensor and an SPI (Serial Peripheral Interface) into an integrated micro-electronic mechanical system sensor; the data processing resolving module adopts a 32-bit ARM (Advanced RISC Machine) microcontroller; and the peripheral communication interface module consists of a serial port level switching chip, an RS-232 interface, a CAN (Controller Area Network) transceiver and a CAN interface. The working method of the system comprises the working steps as follows: the system is electrified and initialized; the system is self-tested; a magnetic field is self-calibrated; initial alignment is conducted;