The invention relates to a construction technical of a cantilever piling and supporting structure combined with sloping. Different from others, the construction technology includes: a), subjecting the pile location of mixing piles to surveying and lining, drilling downwards guniting, promoting mixing of the guniting, drilling downwards once again for mixing of the guniting, repeatedly promoting mixing of the guniting, and displacing a drilling machine; b), subjecting the pile location of supporting piles to surveying and lining, opening a hole in the supporting pile, lifting up a pile casing into the hole, retesting the hole location, well burying the pile casing, mechanically surveying and lining the hole location, forming the hole, placing a reinforcement cage into the pile hole, pouring concrete upwards from the hole bottom, and allowing the elevation of the pile top reach designed elevation of the pile top; c), performing slope excavation, paving steel bar meshes on a slope surface, and spraying concrete on the slope top and the slope surface; d), sorting out pile heads of the supporting piles, setting aside supporting pile steel bars to be anchored into top beams, erecting frameworks and pouring the concrete on the supporting piles to manufacture the top beams and contacting beams, performing stratified excavation on earthwork, and constructing support among the piles. The supporting structure high in integrity is formed, construction is facilitated, and construction speed is high.