The resistivity of metal films grown by magnetron sputtering is one of the important parameters for evaluating and selecting material. In order to obtain high-precision value of film resistivity, Pt films were choosed for investigation, and the four-line method by inverting the Van Pauw function were optimized to design the test system, and the AC/DC four-line method was used to carry out the experimental data acquisition on this system. The experimental results show that the Van der Pauw correction factor f can match the value below 0.7, which expands the application range of the system test. DC four-wire method is found to be more susceptible to the influence of offset voltage and test current, and AC four-wire method has better anti-interference ability than DC four-wire method. In order to evaluate the accuracy of the system test, the results measured by AC four-wire method are compared with those measured by Keithley-2400 source meter and Keithley-2182A nanovolt-meter. The relative error is less than 1.92%. Our test system has practical application, which provides important reference for the uniformity detection of precision films.