The present invention discloses a data transmission method and a terminal. In the method, the terminal supports transmissions with different TTL The method comprises: a base station instructing the terminal to use, on the basis of a target time unit of a target carrier wave, a first TTI for transmitting first data for semi-persistent scheduling and a second TTI for transmitting a second data for dynamic scheduling; and determining, on the basis of respective positions in the target time unit of a first time resource occupied for transmitting semi-persistent scheduling and of a second time resource occupied for transmitting dynamic scheduling, to transmit at least one of the first data and the second data, thereby achieving dynamic scheduling and semi-persistent scheduling using different TTIs.