As an ideal clean fusion fuel, helium-3 (³He) holds broad application prospects. However, its terrestrial reserves are extremely scarce, whereas lunar regolith contains abundant ³He, making large-scale in-situ mining crucial. Because it exists in extremely low concentrations and is primarily enriched within the surface lattices of minerals, such as fine-grained ilmenite, extracting ³He requires a complex and multi-disciplinary engineering system involving physical excavation and thermal processing. This paper presents an architecture for large-scale in-situ ³He mining that encompasses four main stages: excavation, sorting, extraction, and purification. It also defines the collaborative operational workflows among these stages. Building on this framework, this paper introduces an integrated lunar regolith collection vehicle capable of large-scale excavation and sorting, along-side a detailed process flow for ³He extraction and purification. The mining architecture and process flows proposed in this paper establish a theoretical foundation and technical reference for the engineering implementation of future in-situ lunar ³He mining.