From a metamorphic perspective, this paper introduces the research significance, a geological overview of the Himalaya, and the authors research progress on the Himalayan collisional orogenic process in recent years. The Himalayan orogenic belt is a prototype of the continental collisional orogen in the Wilson cycle. The continental collisional process, rules and effects revealed from the Himalaya can be used as a reference for exploring the evolution of collision orogenic belts on Earth from ancient times to the present. Among them, the research on the orogenic mechanism of continental collision is its primary content. Specifically, the controversy of continental collision orogeny mechanisms lies in two endmember mechanisms: Critical Wedge and Channel Flow, which respectively predicted different PTt paths and exhumation spatiotemporal sequences of highgrade metamorphic rocks in the orogenic core. The above disputes can be constrained by studying the PTt paths and exhumation processes of the Himalayan Metamorphic Core (Greater Himalayan Crystalline complex). Consequently, the Himalayan collisional orogeny can be divided into three evolutionary stages. Stage one: 60～40 Ma, “soft” collision period; the crust was thickened to ~40 km and smallscale partial melting occurred; most of these early crustal thickening records have been denuded and are sporadically preserved in the foreland klippes and the northern Himalayan gneiss domes; the Himalaya has risen from below sea level to >1000 meters. Stage two: 40～16 Ma, “hard” collision period; the crust was thickened to 60～70 km, and abundant highgrade metamorphism and anatexis occurred; 〖JP2〗The three subslabs in the Greater Himalayan Crystalline complex were extruded southward sequentially along the "EoHimalayan Thrust", "High Himalayan Thrust" and "Main Central Thrust", forming the core of the Himalayan orogenic belt; the duplex caused uplift of the Himalaya to ≥5000 meters. Stage three: 16～0 Ma, Late collision period; the orogenic root underwent localized foundering due to eclogization; the orogenic belt has not collapsed because IndiaAsia convergent and collision is continuing today; the Lesser Himalaya was exhumed, and the SubHimalaya foreland basin was formed; the Himalayas reached and maintained the current average height of ~6000 meters. In a firstorder, the growth of the Himalaya was dominated by insequence southward expansion, controlled by the Critical Taper model, while the Channel Flow only played a secondary role. The heat flow in the deep orogenic root has a significant transformation effect on the crustal〖JP〗 architecture and topography of the orogenic belt. Future studies should pay attention to the following key scientific issues in the metamorphic research of the Himalayan orogen: ① the relationship between Himalayan extreme metamorphism and major collisional orogenic events; ② the relationship between rare metal mineralization and contact metamorphism in the Himalaya; ③ Himalayan metamorphic decarbonation, and carbon cycle and flux in collisional belts.