Display substrate, preparation method thereof and display device

[0001] A display substrate, its fabrication method, and a display device are disclosed. The display substrate includes a plurality of circuit units (Q), each circuit unit (Q) including at least a first circuit unit (Q1), a second circuit unit (Q2), and a third circuit unit (Q3). The first circuit unit (Q1) includes at least a first driving transistor (DTFT1), the second circuit unit (Q2) includes at least a second driving transistor (DTFT2), and the third circuit unit (Q3) includes at least a third driving transistor (DTFT3). The channel width of the first driving transistor (DTFT1) is greater than the channel width of the second driving transistor (DTFT2) or the third driving transistor (DTFT3), and the channel length of the first driving transistor (DTFT1) is the same as the channel length of the second driving transistor (DTFT2) or the third driving transistor (DTFT3).