The invention discloses a position measurement method for ionized fluorine ions in a fluorine-injection enhanced type HEMT device. The method mainly solves the problem in the prior art that the positions of ionized fluorine ions in existing measurement devices cannot be measured. According to the technical scheme of the invention, firstly, the threshold voltage of the device is measured. Secondly, a reverse stress is applied to the device and the source current, the leakage current and the grid current of the device are monitored and counted. Finally, the threshold voltage of the device is measured after the stress is applied to the device. According to the measured result, the space position of an ionized fluorine ion in the barrier layer of the fluorine-injection enhanced type HEMT device is calculated. The measurement method is simple and reliable, and accurate in measurement result. The subsequent evaluation accuracy for evaluating the performance of the device is improved. Therefore, the method can be used for the process optimization and the analytical characterization of the enhanced type HEMT device.