The invention provides an interlayer connection method of a prefabricated concrete structure and belongs to the technical field of building structures. According to the interlayer connection method of the prefabricated concrete structure, an upper shear wall, a lower shear wall and a floor slab are involved. The floor slab is a prefabricated slab or a composite slab. Steel bars stretch out of the bottom of the upper shear wall, the end of the prefabricated slab or the side edge, close to the shear walls, of the prefabricated slab, and the top of the lower shear wall, the steel bars are sufficiently anchored, and the exposed portions of the steel bars are in a semi-ring shape or an L shape or a straight line shape. The elevation of the bottom face of the upper shear wall is identical to or lower than that of the top face of the floor slab. Grooves are formed in the end of the prefabricated slab at intervals. The upper shear wall, the lower shear wall and floor slab steel bars are connected together. Concrete is poured into gaps between the shear walls. Or when the side edge of the prefabricated slab is parallel to the shear walls, grooves are formed in the side edge of the prefabricated edge at intervals, the upper shear wall, the lower shear wall and the floor slab steel bars are connected together, and concrete is poured into the gaps between the shear walls as well as between the shear walls and the prefabricated slab. By the adoption of the interlayer connection method, the integrity of an integral assembly type concrete structure can be improved.