The invention provides a deep-layer ionic nitriding technology for high carrying capacity of a 35CrMoV gear for a compressor. The technology comprises technological processes including preparing heattreatment, cleaning of a workpiece, feeding for ionic nitriding, ionic nitriding treatment, infiltration layer inspection for ionic nitriding and the like. According to the technology, on the basis that the core hardness is improved, the technological method with the surface hardness, the surface brittleness, veined nitride and the like completely qualified and the infiltration layer depth up to 1.0 mm is successfully tested, the ionic nitriding infiltration layer thickness of the workpiece subjected to circulating variable-temperature four-stage ionic nitriding technological treatment is substantially increased, the infiltration layer hardness gradient is more stable, the carrying capacity of the gear is substantially improved, and the contact fatigue and the bending strength are substantially improved.