NOVELTY - Preparation of transparent low- or high-resistance composite thin film of thin film solar battery comprises placing sample on which composite thin film grows and conducting oxide target material into vacuum chamber of magnetron sputtering device; vacuumizing vacuum chamber until vacuum degree is 4-8x 10-4 Pa; setting magnetron sputtering parameters at sputtering power of 50-100 W, sputtering gas of argon (Ar) and oxygen (O2), and sputtering atmospheric pressure of 0.8-2.4 Pa, where volume percentage of O2 is controlled through regulating the flow rate of Ar and O2.    USE - Method of preparing transparent low- or high-resistance composite thin film of thin film solar battery having upper or lower configuration (claimed).    ADVANTAGE - Because the same target material is used, the transparent low- or high-resistance composite thin film or transparent composite thin film with resistance gradient is prepared, by only varying the oxygen content in the sputtering atmosphere without damaging the vacuum environment in the same vacuum chamber. Thus, the production processes are reduced and the production cycle is shortened. The method is simple and easy to operate. The production cost is greatly lowered.    DETAILED DESCRIPTION - Preparation of transparent low- or high-resistance composite thin film of thin film solar battery comprises:    (A) placing sample on which transparent low- or high-resistance composite thin film grows and conducting oxide target material into vacuum chamber of a magnetron sputtering device; and vacuumizing the vacuum chamber with a mechanical pump and a molecular pump until vacuum degree is 4-8x 10-4 Pa;    (B) setting magnetron sputtering parameters at sputtering power of 50-100 W, sputtering gas of Ar and O2, and sputtering atmospheric pressure of 0.8-2.4 Pa, where volume percentage of O2 is controlled through regulating the flow rate of Ar and O2, temperature of sample is 300-500 degrees C, and sputtering time depends on the film thickness; and    (C) growing the low- or high-resistance composite thin film (where sample is a transparent substrate for thin film solar battery having a structure of the upper configuration) by growing a transparent low-resistance film on transparent substrate in the sputtering gas of pure Ar through sputtering, where thickness of film is set as required; growing a transparent high-resistance film on the transparent low-resistance film in the mixed working gas of Ar and O2 through sputtering, where O2 content is 1-15% and film thickness is set as required; stopping the heating of the substrate after sputtering; and cooling the thin film sample to room temperature together with substrate table, where in thin film solar battery having a structure of the lower configuration, the sample comprises rear contact electrode, p-type absorption layer, and n-type window layer prepared on the substrate in sequence, and where on the n-type window layer, the transparent high- and low-resistance films grow in sequence, and the growth conditions of the transparent high- and low-resistance films are the same as the structure of the upper configuration.