Actual experimental data under standard test conditions at open circuit point, short circuit point and maximum power point are provided by photovoltaic module manufacturer. Based on these data, nonlinearity equations with light current, diode ideality factor, equivalent series and shunt resistances are built and solved with Newton-Raphson algorithm. Aiming at the parametric drifting problem of the other four parameters’ calculating results, when the initial value of diode ideality factor is selected improperly, an equivalent correction algorithm is proposed. Eliminating the diode ideality factor, an equivalent equation is built. Besides, an iterative parametric correction strategy is put forward as well. Theoretical analysis shows, with the method proposed in this paper, the diode ideality factor value is no longer estimated according to someone’s experience, and the equivalent series and shunt resistances are no longer neglected. What’s more, the iterative parametric correction strategy ensures accurate model parameters can be obtained through a small amount of iteration. The accuracy of the algorithm is validated based on the actual experimental data analysis of MSX60 photovoltaic module.