The invention provides a flower planting device for pedestrian overcrossings, and belongs to the technical field of municipal engineering. The flower planting device for the pedestrian overcrossings comprises a bridge plate, a first walking stair, a second walking stair, a first guard bar, a second guard bar, first flowerpots, second flowerpots, a first flower growing box, a second flower growingbox, a first pruning piece, a second pruning piece, a first drip irrigation piece and a second drip irrigation piece. The flower planting device for the pedestrian overcrossings has the advantages that the first flowerpots are arranged in the first flower growing box, the second flowerpots are arranged in the second flower growing box, the first drip irrigation piece waters the first flowerpots, the second drip irrigation piece waters the second flowerpots, so that first flowers and second flowers thrive respectively, the first pruning piece prunes the first flowers stretching out of the firstflowerpots, and the second pruning piece prunes the second flowers stretching out of the second flowerpots to cut off withered branches or overgrown branches, thereby avoiding the waste of nutrient,and avoiding the situation that vehicles are hindered from walking, the structure is simple, and the operation is simple and convenient.