A magnetic sensing switch includes switch body having a hollow tube and an opening. A magnetic reed switch is disposed in the tube and includes two conductive points. The plug having an elastic clamping force is fixed in the opening by interference fit. The plug including a sealant injection portion and a retaining portion communicating with the tube. The two wires are inserted in the tube, one end of each wire is connected to one conductive point, and the other end passes through the retaining portion to protrude out of the tube. A sealant is injected into the tube via the sealant injection portion to entirely wrap the magnetic reed switch and the wires inside the tube, and the sealant partially protrudes out of the sealant injection portion.