A method for transmitting an alert message, comprising: obtaining physical characteristic data of a target object on a target device; and transmitting a first alert message to a first terminal, if a preset matching condition is not satisfied between the physical characteristic data of the target object and pre-stored physical characteristic data of a target user, wherein said step of transmitting a first alert message to a first terminal, if a preset matching condition is not satisfied between the physical characteristic data of the target object and pre-stored physical characteristic data of a target user, comprises: determining a physical characteristic data range corresponding to the pre-stored physical characteristic data of the target user; and transmitting the first alert message to the first terminal, if the physical characteristic data of the target object is not within the physical characteristic data range, characterized in that the method further comprises: obtaining motion data of the target user within a preset time period; and adjusting the physical characteristic data range based on the motion data; wherein said transmitting the first alert message to the first terminal, if the physical characteristic data of the target object is not within the physical characteristic data range, comprises: transmitting the first alert message to the first terminal, if the physical characteristic data of the target object is not within the adjusted physical characteristic data range. obtaining physical characteristic data of a target object on a target device; and transmitting a first alert message to a first terminal, if a preset matching condition is not satisfied between the physical characteristic data of the target object and pre-stored physical characteristic data of a target user, wherein said step of transmitting a first alert message to a first terminal, if a preset matching condition is not satisfied between the physical characteristic data of the target object and pre-stored physical characteristic data of a target user, comprises: determining a physical characteristic data range corresponding to the pre-stored physical characteristic data of the target user; and transmitting the first alert message to the first terminal, if the physical characteristic data of the target object is not within the physical characteristic data range, determining a physical characteristic data range corresponding to the pre-stored physical characteristic data of the target user; and transmitting the first alert message to the first terminal, if the physical characteristic data of the target object is not within the physical characteristic data range, characterized in that the method further comprises: obtaining motion data of the target user within a preset time period; and adjusting the physical characteristic data range based on the motion data; obtaining motion data of the target user within a preset time period; and adjusting the physical characteristic data range based on the motion data; wherein said transmitting the first alert message to the first terminal, if the physical characteristic data of the target object is not within the physical characteristic data range, comprises: transmitting the first alert message to the first terminal, if the physical characteristic data of the target object is not within the adjusted physical characteristic data range. transmitting the first alert message to the first terminal, if the physical characteristic data of the target object is not within the adjusted physical characteristic data range.