A combination structure for a labyrinth includes plural labyrinth units, which are combined into various labyrinths, respectively composed of four frame rods, a reinforcing support bar and plural fixing members. The four frame rods have their ends butt jointed to form into a square, each frame rod is formed with two connecting ends respectively cut with a recess and provided with an insert hole and each having its wall bored with plural insert holes. The reinforcing support bar is obliquely set inside the four frame rods and formed with two connecting ends respectively bored with an insert hole and having two sides respectively cut with a lengthwise recess. The fixing members are inserted in the insert holes of the connecting ends of the four frame rods and of the reinforcing support bar for securing the four frame rods and the reinforcing support bar together to form a labyrinth unit.