The invention relates to the field of building engineering, in particular to a basement exterior wall construction method and structure. In the method, an underground continuous wall in foundation pitsupporting is used as a part of a basement side wall, so that a basement exterior wall is thinned; besides, by directly using the underground continuous wall as an outer form of a basement floor, a floor slab and the exterior wall, expansion force generated by concrete of the basement floor, the floor slab and the exterior wall in the pouring and setting process is effectively resisted; meanwhile, the concrete of the basement floor, the floor slab and the exterior wall has no exposed part on the outer side, so that the concrete is in a good curing state and not likely to crack; by taking themeasures of arranging a hidden beam in the floor of the basement exterior wall, arranging a flexible coiled material on the basement floor and the like, the generation of cracks in the basement concrete construction process is effectively controlled.