ReaxFF molecular dynamics （ReaxFF MD） simulations were adopted to identify the main intermediate products， final products and chemical reactions during 3，4-dinitro-1H-pyrazole （DNP） thermal decomposition. Accelerating rate calorimeter （ARC）-mass spectrometer （MS） technique was adopted to study DNP thermal decomposition properties and identify the gaseous products. The simulated results illustrate that C₃HO₄N₄， C₃HO₃N₄， C₃HO₂N₃， C₃HNO₂， NO₂ are the main intermediate products， and H₂O， CO₂， N₂ are the main final products. MS detected main gaseous products are H₂O， CO₂， N₂ as well. According to the simulation results， the produced time and abundance of the products are obtained as well. Among which C₃HO₃N₄ is the first generated intermediate product， and H₂O is the first generated final product. C₃HO₃N₄ and N₂ are the intermediate and final products with the largest amount， respectively. Additionally， the main chemical reactions in DNP thermal decomposition process are also acquired by molecular dynamics simulations. According to the generation time and abundance of products， the decomposition path of DNP was obtained.