A doorbell-triggering method first controls the doorbell trigger to switch to a hardware shutdown status when detecting the doorbell trigger is idle; controls the doorbell trigger to switch to an operating booting status to connect to a relay host when receiving a doorbell signal from a button unit of the doorbell trigger under the hardware shutdown status; sends a visiting message to a remote electronic device via the relay host; receives a return image/text message from the relay host and displaying the return image/text message on a display unit of the doorbell trigger. The present disclosed example can substantially reduce the power consumption and the requirement of network bandwidth via automatically switching to the hardware shutdown status when idle and using the image/text message having smaller data size to respond the visitor.