The invention discloses a p-type CuMSnO amorphous oxide semiconductor thin film. M is selected from group-III elements B, Al, Ga, In, Sc and Y. Cu and Sn are commonly used as basic elements of a material; the Cu has a <+1> valence and the Sn has a <+2> valence, and the Cu and the Sn are combined with O to form a p-type conducting property of the material; the M has a <+3> valence, has a relatively low standard electrode potential and has high combining energy with the O; the M is used as a control element of hole concentration; meanwhile, the Sn has a spherical electron orbit and electron clouds can be greatly overlapped under an amorphous state, so that the Sn also has the effect of a hole transportation channel. The invention further discloses a preparation method of the p-type CuMSnO amorphous oxide semiconductor thin film and application of the p-type CuMSnO amorphous oxide semiconductor thin film to thin film transistors. The prepared thin film has the hole concentration of 10<14>cm<-3> to 10<15>cm<-3> and the visible light transmittance is more than or equal to 80 percent. A p-type CuAlSnO amorphous thin film is a channel layer; a TFT (Thin Film Transistor) prepared by the p-type CuAlSnO amorphous thin film has the on/off current ratio of (1 to 9)*10<4> and the field-effect mobility of 0.4cm<2>/Vs to 5cm<2>/Vs.