Based on the mid-infrared tunable diode laser absorption spectroscopy, we study the measurement method of nitric oxide (NO) with low concentrations and high signal-to-noise ratios. A mid-infrared NO absorption line at about 1926 cm -1 with strong absorption line strength is selected, and the NO measurement at ambient temperature is conducted with wavelength modulation method using an interband cascade laser (ICL). By changing the modulation parameters of the ICL, we investigate measurement results and signal-to-noise ratios of NO with different volume fractions (0.46×10 -4-1.31×10 -4) at different modulation currents (3-25 mA). The results show that the signal-to-noise ratio is the best when the modulation current is 11 mA. The measurement results of NO with volume fractions from 0.5×10 -5 to 2.0×10 -5 have high signal-to-noise ratios.