The disclosure provides a data transmission method and a terminal in an Internet of Vehicles (IoV) system. In the embodiment of the present disclosure, the terminal may implement the data transmission method in the IoV system by determining a data transmission mode of a first carrier, then obtaining the multi-carrier transmission parameter of the first carrier if the data transmission mode of the first carrier is a multi-carrier transmission mode, and transmitting data on the first carrier using the multi-carrier transmission parameter.