A method for coding and modulating data, comprising: obtaining, from a receiver and a transmitter, parameters for calculating power consumption of the transmitter; calculating, according to the parameters, the power consumption of the transmitter under various combinations of modulation orders and coding rates supported by the transmitter; and selecting a modulation bitwidth of the transmitter, modulation order, and coding rate corresponding to minimum power consumption of the transmitter to code and modulate data sent to the receiver; wherein the parameters comprise a supported modulation bitwidth of the receiver fed back by the receiver and a modulation bitwidth feature of the transmitter; characterized by: wherein the calculating, according to the parameters, the power consumption of the transmitter under various combinations of modulation orders and coding rates supported by the transmitter is: determining an upper modulation bitwidth threshold of the transmitter according to the supported modulation bitwidth of the receiver, obtaining a quantized noise of the transmitter by calculation, and using a modulation bitwidth of the transmitter corresponding to the quantized noise as a lower modulation bitwidth threshold; and in a range between the upper modulation bitwidth threshold and the lower modulation bitwidth threshold, selecting a plurality of available modulation bitwidths of the transmitter, and respectively calculating power consumption of the transmitter under the plurality of available modulation bitwidths of the transmitter. obtaining, from a receiver and a transmitter, parameters for calculating power consumption of the transmitter; calculating, according to the parameters, the power consumption of the transmitter under various combinations of modulation orders and coding rates supported by the transmitter; and selecting a modulation bitwidth of the transmitter, modulation order, and coding rate corresponding to minimum power consumption of the transmitter to code and modulate data sent to the receiver; wherein the calculating, according to the parameters, the power consumption of the transmitter under various combinations of modulation orders and coding rates supported by the transmitter is: determining an upper modulation bitwidth threshold of the transmitter according to the supported modulation bitwidth of the receiver, obtaining a quantized noise of the transmitter by calculation, and using a modulation bitwidth of the transmitter corresponding to the quantized noise as a lower modulation bitwidth threshold; and in a range between the upper modulation bitwidth threshold and the lower modulation bitwidth threshold, selecting a plurality of available modulation bitwidths of the transmitter, and respectively calculating power consumption of the transmitter under the plurality of available modulation bitwidths of the transmitter. determining an upper modulation bitwidth threshold of the transmitter according to the supported modulation bitwidth of the receiver, obtaining a quantized noise of the transmitter by calculation, and using a modulation bitwidth of the transmitter corresponding to the quantized noise as a lower modulation bitwidth threshold; and in a range between the upper modulation bitwidth threshold and the lower modulation bitwidth threshold, selecting a plurality of available modulation bitwidths of the transmitter, and respectively calculating power consumption of the transmitter under the plurality of available modulation bitwidths of the transmitter.