The invention discloses an inertial navigation indoor positioning system and a use method thereof. The system comprises a positioning module and a receiving module, the positioning module mainly comprises a calculating and processing module, an emission module and a gyroscope, one side of the calculating and processing module in the positioning module is provided with an error calibration module, the gyroscope is communicated with the calculating and processing module and the error calibration module, the calculating and processing module is communicated with the emission module, and the emission module is wirelessly communicated with the receiving module. The system can realizes accurate positioning in firefighting or rescue and relief work places without arranging basic points in advance. Human body pace data is acquired by the gyroscope, is calculated and analyzed by the calculating and processing module, is received by the receiving module, and is introduced to a computer, the position information of personnel is monitored in real time, and the pace data undergoes error detection and error correction through the error calibration module to make position information transmitted to command personnel be accurate.