Determining the characteristic parameters of solar cells is not only the foundation for establishing their current voltage equation, but also the key to understanding the nonlinear device of solar cells. In this paper, a simple experimental method was built to determine these characteristic parameters. Firstly, the current and voltage of the solar cell under non-standard test conditions and dark conditions were measured, the current and voltage under standard test conditions were derived by correction. Secondly, light current, diode reverse saturation current, ideality factor, series resistance and shunt resistance of the solar cell under standard test conditions were determined based on the proposed model. And the current-voltage equation of the solar cell was established. Finally, by comparing the curve of the current voltage equation with the corrected measurement results, it is found that the root mean square error of the current in this method is less than 0.12A, which can meet the requirements of the experiment. This method helps to enhance students' understanding of the nonlinear output performance of solar cells.