The invention discloses an aluminum alloy building formwork splicing assembly which comprises multiple groups of formworks transversely laid along floor slabs to be cast. Multiple groups of supporting beams connected with the formworks and provided with gaps are arranged among the formworks, a fixing block fixed to the supporting beams and provided with a guiding groove is arranged at the intersection position of every two adjacent supporting beams, jacking parts matched with the gaps, provided with the top faces acting on the floor slabs and provided with connecting grooves are arranged between two fixing blocks, the top faces of the jacking parts, the formworks and the supporting beams jointly form a floor slab formwork for floor slab casting, connecting pieces fixedly connected with the fixing blocks are arranged in the guide grooves and the connecting grooves. The aluminum alloy building formwork splicing assembly further comprises adjustable supporting rods arranged on the ground, with the top ends in plugged connection with the jacking parts and used for jacking the formworks and the supporting beams. The aluminum alloy building formwork splicing assembly is simple in structure, convenient to splice, high in efficiency, good in overall stability, small in scaffold number, economic and efficient.