A nonlinear precoding bit loading method in a DSL system, comprising: determining, by a receive end, power control factors of multiple preset quantities of bits, wherein the receive end supports information transmission in multiple bit loading modes, and the multiple bit loading modes refer to multiple modes in which the multiple preset quantities of bits are separately loaded on a single subcarrier wherein the step of determining uses a power control factor determining rule which is a corresponding function relationship between non-linear precoding modulo values of the multiple preset quantities of bits and the power control factors, the non-linear precoding modulo values being calculated according to a preset modulo value determining rule based on the formula: M b = 2 M B b + 10 CG 20 where M = 2 b, 1≤b≤B_max, b indicates the preset quantity of bits, B_max indicates a maximum quantity of bits supported by the system, M b indicates a nonlinear precoding modulo value of b bits, CG indicates a precoding gain, and MB b indicates a maximum horizontal or vertical boundary of the quadrature amplitude modulation, QAM, constellation diagram of b bits; obtaining, by the receive end, a first correspondence table between the multiple preset quantities of bits and signal to noise ratios without power control; determining, by the receive end, a second correspondence table between the multiple preset quantities of bits and signal to noise ratios with power control according to the power control factors and the first correspondence table, wherein each of the power control factors reflects a relationship between a signal to noise ratio without power control and a signal to noise ratio with power control; and after actually measuring a signal to noise ratio with power control on the subcarrier, determining, by the receive end according to the second correspondence table, a preset quantity of bits corresponding to the actually measured signal to noise ratio with power control, using the determined preset quantity of bits as an actual bit loading quantity of the single subcarrier, and notifying a transmit end of the actual bit loading quantity. determining, by a receive end, power control factors of multiple preset quantities of bits, wherein the receive end supports information transmission in multiple bit loading modes, and the multiple bit loading modes refer to multiple modes in which the multiple preset quantities of bits are separately loaded on a single subcarrier wherein the step of determining uses a power control factor determining rule which is a corresponding function relationship between non-linear precoding modulo values of the multiple preset quantities of bits and the power control factors, the non-linear precoding modulo values being calculated according to a preset modulo value determining rule based on the formula: M b = 2 M B b + 10 CG 20 where M = 2 b, 1≤b≤B_max, b indicates the preset quantity of bits, B_max indicates a maximum quantity of bits supported by the system, M b indicates a nonlinear precoding modulo value of b bits, CG indicates a precoding gain, and MB b indicates a maximum horizontal or vertical boundary of the quadrature amplitude modulation, QAM, constellation diagram of b bits; obtaining, by the receive end, a first correspondence table between the multiple preset quantities of bits and signal to noise ratios without power control; determining, by the receive end, a second correspondence table between the multiple preset quantities of bits and signal to noise ratios with power control according to the power control factors and the first correspondence table, wherein each of the power control factors reflects a relationship between a signal to noise ratio without power control and a signal to noise ratio with power control; and after actually measuring a signal to noise ratio with power control on the subcarrier, determining, by the receive end according to the second correspondence table, a preset quantity of bits corresponding to the actually measured signal to noise ratio with power control, using the determined preset quantity of bits as an actual bit loading quantity of the single subcarrier, and notifying a transmit end of the actual bit loading quantity.