Methods, systems, and apparatus, including computer programs encoded on computer storage media, for identity verification are provided. One of methods, implemented by a mobile terminal device, includes: obtaining a device identifier of a service device configured to provide a service based on a digital key; uploading the device identifier to a server in communication with the service device and the mobile terminal device and storing registration information of service devices, to cause the server to perform validity verification on the device identifier; in response to receiving a result indicating the device identifier is valid, collecting identity feature information of a user; uploading the identity feature information of the user to the server, to cause the server to perform identity verification on the user based on the identity feature information; and obtaining the digital key issued by the server in response to the identity verification being successful.