Disclosed is a display driving method, an upper machine, a lower machine and a display driving system. The method includes: acquiring, by a lower machine, an address for any of subpixels transmitted from an upper machine; looking up, by the lower machine, a gray scale data corresponding to the pointer address in a display Look-UP Table (LUT), wherein the LUT stores mapping relationships between respective pointer addresses and their corresponding gray scale data; performing, by the lower machine, a digital-analog conversion on the gray scale data to acquire a converted analog voltage; and outputting the analog voltage to the subpixel so as to drive the subpixel for displaying. The method can increase the transmission rate between the GPU and the display to a certain degree and reduce the power consumption thereof.