The invention mainly discloses a method and system for monitoring the working state of a photovoltaic power station, and avoids the influence of temperature factors on the monitoring of the working state of the photovoltaic power station and reduces the misjudgment rate of the working state of the photovoltaic power station. According to the method and the system, the preliminary judgment is carried out through the ratio of the current change rate to the temperature change rate; meanwhile, auxiliary judgment is carried out by utilizing the ratio of the voltage change rate to the temperature change rate; through the combination of preliminary judgment and auxiliary judgment, whether the working state of the solar cell string connected with the input end of the combiner box or the working state of the former-stage combiner box is normal or not is determined. Moreover, a phase-change material is added to the backlight side of the solar cell panel to adaptively adjust the temperature of the solar cell panel, so that the influence of temperature factors on the monitoring of the working state of the photovoltaic power station is effectively reduced, the monitoring accuracy is improved, and the photoelectric conversion efficiency of the solar cell panel is improved at the same time.