An electromagnetic transmission device. A guide bar connects to a fixed base and includes magnetic-permeable material and a first central height plane. A coil connects to the fixed base. A support base movably fits on the guide bar. An annular magnetic member connects to the support base and is surrounded by the coil. A magnetization direction of the annular magnetic member is perpendicular to a moving direction of the support base and annular magnetic member. The annular magnetic member includes a second central height plane. The coil interacts with the annular magnetic member to generate a first force. When moving to separate the second central height plane from the first central height plane, the annular magnetic member interacts with the guide bar to generate a second force, driving the support base and annular magnetic member to move along a direction perpendicular to the magnetization direction of the annular magnetic member.