Temperature and current tuning characteristics of distributed feedback laser and absorption lines distribution of HF gas in near infrared was investigated,generalized Lorentz functions was used to realize rapid approximate calculation of Voigt function.The Voigt profile fitting of absorbance and the inversion of gas concentration for wavelength scanning technology.A tunable diode laser absorption spectroscopy system for HF gas concentration measurement was designed,using one absorption line of HF gas near 1.28 μm as the target absorption line,using known standard concentration HF gas for preparation of different concentration HF gas to measurement.The detection limit is 1.12 ppm-m.The system has high measurement accuracy and long-term operate stability,satisfies the needs of HF gas real-time online monitoring.