The present disclosure provides a thin film transistor, a display substrate, a method for preparing the same, and a display device including the display substrate. The method for preparing the thin film transistor includes: forming an inorganic insulating film layer in contact with an electrode of the thin film transistor by a plasma enhanced chemical vapor deposition process at power of 9 kW to 25 kW, at a temperature of 190° C. to 380° C. and by using a mixture of gases N2, NH3 and SiH4 in a volume ratio of N2:NH3:SiH4=(10˜20):(5˜10):(1˜2), such that a stress value of the inorganic insulating film layer is reduced to be less than or equal to a threshold, and the inorganic insulating layer comprises silicon nitride.