In order to achieve the purpose of long-range gas detection, a mid-infrared laser with dual wavelength output is developed; this system is based on an optical parametric oscillator composed of superlattice materials. The optical parametric oscillator realizes a mid-infrared pulsed laser output of nanosecond order with a 500 Hz repetition rate and a single pulse energy that exceeds 1 mJ through seed injection, and effectively aligns the NO, NO₂, and SO₂ absorption peaks in the 2.6‒4.0 μm range. The laser performance is validated in a remote gas detection experiment based on a gas dynamic emission experiment.