A method for data transmission, comprising: generating (S101, S201, S301, S401, S501) an acknowledgment message for indicating successful data reception in response to detecting that first downlink data is received by a terminal; acquiring (S102, S203, S303, S403, S503) a channel resource occupancy priority of the acknowledgment message; and transmitting (S103, S204, S304, S404, S504) the acknowledgment message via a preset channel resource, when the channel resource occupancy priority of the acknowledgment message is detected to be higher than a channel resource occupancy priority of second downlink data, the second downlink data being data to be received by the terminal, characterized in that the method further comprising one of the following after generating the acknowledgment message and prior to acquiring the channel resource occupancy priority of the acknowledgment message: setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when a downlink-data-receiving speed of the terminal is detected to be higher than an uplink-data-transmitting speed of the terminal; setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when a difference between a downlink-data-receiving speed of the terminal and an uplink-data-transmitting speed of the terminal is detected to be greater than or equal to a first preset threshold; setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when the amount of downlink data received by the terminal during a preset time period is detected to be greater than or equal to a second preset threshold; and setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when the amount of uplink data transmitted by the terminal during a preset time period is detected to be less than or equal to a third preset threshold. generating (S101, S201, S301, S401, S501) an acknowledgment message for indicating successful data reception in response to detecting that first downlink data is received by a terminal; acquiring (S102, S203, S303, S403, S503) a channel resource occupancy priority of the acknowledgment message; and transmitting (S103, S204, S304, S404, S504) the acknowledgment message via a preset channel resource, when the channel resource occupancy priority of the acknowledgment message is detected to be higher than a channel resource occupancy priority of second downlink data, the second downlink data being data to be received by the terminal, characterized in that the method further comprising one of the following after generating the acknowledgment message and prior to acquiring the channel resource occupancy priority of the acknowledgment message: setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when a downlink-data-receiving speed of the terminal is detected to be higher than an uplink-data-transmitting speed of the terminal; setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when a difference between a downlink-data-receiving speed of the terminal and an uplink-data-transmitting speed of the terminal is detected to be greater than or equal to a first preset threshold; setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when the amount of downlink data received by the terminal during a preset time period is detected to be greater than or equal to a second preset threshold; and setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when the amount of uplink data transmitted by the terminal during a preset time period is detected to be less than or equal to a third preset threshold. setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when a downlink-data-receiving speed of the terminal is detected to be higher than an uplink-data-transmitting speed of the terminal; setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when a difference between a downlink-data-receiving speed of the terminal and an uplink-data-transmitting speed of the terminal is detected to be greater than or equal to a first preset threshold; setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when the amount of downlink data received by the terminal during a preset time period is detected to be greater than or equal to a second preset threshold; and setting the channel resource occupancy priority of the acknowledgment message to be higher than the channel resource occupancy priority of the second downlink data, when the amount of uplink data transmitted by the terminal during a preset time period is detected to be less than or equal to a third preset threshold.