This study designs a mobile APP of elevator booking system, designating to solve the problems of the reservation site and booking method immutable. The system accesses the key technology to realize the remote client and field device data sharing and remote monitoring by using the elevator data acquisition, control terminal, and server database. The field devices establish a link with the server link using RS485 bus, through the embedded elevator controller. The APP completes the client real-time updates data according to the elevator running characteristics of the development of mobile applications. The design is based on the Android system, with equip went of the elevator location display, the number of elevator monitoring, remote call, and elevator to remind the station and other functions. These functions can choose the suitable time for users according the elevator using status.