A data transmission method carried out in a terminal in an Internet of Vehicles (IoV) based on direct terminal to terminal communication, comprising: determining whether a data transmission mode of a first carrier that is being used is a multi-carrier transmission mode ; obtaining a multi-carrier transmission parameter of the first carrier, if the data transmission mode of the first carrier is a multi-carrier transmission mode; and performing data transmission on the first carrier by using the multi-carrier transmission parameter, characterized in that the step of determining the data transmission mode of the first carrier comprises: determining whether the first carrier is used to carry signal for one first transmission entity together with at least one second carrier; and determining that the data transmission mode of the first carrier is the multi-carrier transmission mode, if the first carrier is used to carry signal for the one first transmission entity together with the at least one second carrier, wherein, the first transmission entity comprises an RLC entity; one RLC entity corresponds to one logical channel, and wherein the multi-carrier transmission parameter comprises at least one of transmission power limitation, coding and modulation mode limitation, subchannel number limitation, and physical resource block (PRB) number limitation. determining whether a data transmission mode of a first carrier that is being used is a multi-carrier transmission mode ; obtaining a multi-carrier transmission parameter of the first carrier, if the data transmission mode of the first carrier is a multi-carrier transmission mode; and performing data transmission on the first carrier by using the multi-carrier transmission parameter, characterized in that the step of determining the data transmission mode of the first carrier comprises: determining whether the first carrier is used to carry signal for one first transmission entity together with at least one second carrier; and determining that the data transmission mode of the first carrier is the multi-carrier transmission mode, if the first carrier is used to carry signal for the one first transmission entity together with the at least one second carrier, wherein, the first transmission entity comprises an RLC entity; one RLC entity corresponds to one logical channel, and wherein the multi-carrier transmission parameter comprises at least one of transmission power limitation, coding and modulation mode limitation, subchannel number limitation, and physical resource block (PRB) number limitation. determining whether the first carrier is used to carry signal for one first transmission entity together with at least one second carrier; and determining that the data transmission mode of the first carrier is the multi-carrier transmission mode, if the first carrier is used to carry signal for the one first transmission entity together with the at least one second carrier, wherein, the first transmission entity comprises an RLC entity; one RLC entity corresponds to one logical channel, and wherein the multi-carrier transmission parameter comprises at least one of transmission power limitation, coding and modulation mode limitation, subchannel number limitation, and physical resource block (PRB) number limitation. <EOS>