The invention provides a quantum dot light emitting diode device and a preparation method thereof, and a display panel. The preparation method of the quantum dot light emitting diode device comprisesthe following steps: an anode layer, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and a cathode layer are laminated on a substrate in sequence; preparing a plurality of spaced color film regions on a first cover plate and a second cover plate respectively, and forming a red pixel layer and a green pixel layer in the color film region respectively, forming a first color film layer and a second color film layer on the first cover plate and the second cover plate respectively, wherein the hydrophilicity and hydrophobicity of the adjacent twocolor film regions are different; pressing a first color film layer formed on the first cover plate and a substrate pair group and pressing the second color film layer and the cathode layer formed onthe second cover plate together to form the quantum dot light emitting diode device, thereby realizing the preparation of the double-sided full-color quantum dot light emitting diode device by a solution state manufacturing process, simplifying the preparation process and reducing the preparation cost.