The invention discloses an electric vehicle-mounted terminal data transmission method applied to remote monitoring. Two kinds of communication protocols exist in a remote monitoring application of a vehicle-mounted terminal; a CAN (Controller Area Network) bus communication protocol defined by a vehicle manufacturer is followed between the vehicle-mounted terminal and a vehicle; a platform protocol is followed between the vehicle-mounted terminal and a monitoring platform; and a format of CAN bus data and a storage format of the CAN bus data in the platform protocol are redefined, so that the vehicle-mounted terminal can adapt to a new vehicle bus protocol, and a uniform protocol specification is kept between the vehicle-mounted terminal and the monitoring platform. Through adoption of the method, a vehicle-mounted terminal firmware and a monitoring platform service program do not need to be modified, the data format of the vehicle-mounted terminal is standardized, and a formatted data structure is transmitted to the terminal in order to adapt to the new bus protocol, so that the system adaptability is enhanced, and the system maintenance burden is lowered.