A building block device with 35 units as variable combinations, including a storage box and a building block group, the storage box comprises a base and a top cover covering the base, the building block group comprises multiple building blocks, the base has a storage tank for placing the building block group, the top cover can cover the base to conceal the building block group; the bottom of the storage tank is provided with 35 locating grids for the building block group to form a single-layer planar pattern, the surface of the top cover is provided with 15 locating slots for the building block group to stack up a five-layer trilateral cone, each building block of the building block group comprises one to five units, the units are connected at horizontally or vertically two-dimensional angles, the building block group has 35 units.