Understanding the distribution characteristics of atmospheric components and parameters at different altitudes plays a crucial role in deeply comprehending climate change and addressing climate issues. To meet the detection requirements for vertical profiles of multiple atmospheric components （H₂O，CO₂，CH₄，N₂O，O₃，CO， etc.） and line-of-sight wind speed， this study designs an LEO-LEO infrared laser occultation （LIO） system. For payload design， the laser transmitter employs broadband frequency-locked laser source technology to generate highly stable infrared lasers. The receiver utilizes multi-grating spatial heterodyne spectroscopy （SHS）， achieving wide spectral coverage （2-2.5 μm） and high spectral resolution （≤0.15 cm^-1）. For data application and orbit simulation， an Abel transform-based inversion method is proposed to synchronously retrieve atmospheric composition and parameter profiles in the Upper Troposphere and Lower Stratosphere （UTLS）. Additionally， a simulated occultation orbit system demonstrates a daily occultation event frequency of up to 61 times， with optimized data acquisition processes for single events.