The invention discloses an electromagnet. The electromagnet ensures that a large end hole edge of a taper hole coincides with the peripheral surface of a plugging part or the peripheral surface of a columnar armature, so that the areas of a large end opening of the taper hole and a hole wall surface of the taper hole are increased, and when an electromagnetic coil is powered on, the suction between the columnar armature and a stopping seat is larger than that of a columnar armature and a stopping seat in the prior art, so that the columnar armature and the stopping seat of the electromagnet have higher actuation strength under the condition of identical current strength in the electromagnetic coil, electric power resource is saved, and the operational reliability of the electromagnet is correspondingly improved.