Disclosed is a driver of an ethernet transmitter and a control method therefor. The driver has a first output port and a second output port connected to an ethernet receiver through a transmission line, and comprises: a signal conversion module for converting differential current signals into a first voltage signal and a second voltage signal; a first driving module adjusting a swing of the first voltage signal, to obtain a first output signal having a voltage equal to the first voltage signal; a second driving module adjusting a swing of the second voltage signal, to obtain a second output signal having a voltage equal to the second voltage signal. An architecture having a relatively small area is realized, and the ethernet transmitter meets the requirement on a large output swing in 10BASE-T mode.