An anti-interference switch signal transmission circuit, in which a changeover switch is used at a signal terminal, is disclosed. A normally closed contact is connected to DC−, a normally open contact is connected to DC+, and a common contact is connected to a switch signal acquisition circuit. When no signal exists, DC− is provided to a positive input terminal of the switch signal acquisition circuit via the normally closed contact. Since a negative input terminal of the switch signal acquisition circuit is also connected to DC−, even if interference is caused, no false signal is generated. When a signal exists, the position of the changeover switch changes and DC+ is connected to DC− via the closed normally open contact through the switch signal acquisition circuit thus a loop is formed, so that the signal can be detected.