A method for sending an alarm message, and belongs to the field of computer technology. The method includes: acquiring a detection image (201) captured by an image capturing apparatus; determining a target detection area (202); and detecting a person's call status information corresponding to an image in the target detection area according to a preset on-the-phone determination algorithm model, and sending a first alarm message (203) to a server if the person's call status information shows that the person is on the phone.