Monitoring hydrogen sulfide is very important for controlling the risk of leakage and protecting the environment safety. Tunable diode laser absorption spectroscopy, which takes the advantages of high sensitivity, speed and specificity, has a very broad application prospect in the field of gas online detection. In this paper, the hydrogen sulfide gas detection method is proposed based on tunable laser absorption spectroscopy and the calibration method to eliminate the effect of pressure and temperature. The measuring system applies both temperature and current tuning protocol to achieve larger tuning range, higher tuning speed and stability. Based on the lockin technology, the second harmonic are extraction from the absorption signal of hydrogen sulfide. By analyzing the influence of gas pressure and temperature on the absorption spectrum, the calibration method based on parameter fitting is proposed. The results show that the detection system achieves high sensitivity in hydrogen sulfide detection. The calibration method is effective in eliminating the influence of gas temperature and pressure.