The invention relates to a method for jointly evaluating the insulation state of oil paper by using multiple statistical parameters, characterized by comprising the following steps of: using an ultra-wideband partial discharge detection system to perform partial discharge detection on the oil paper insulation in a power device; collecting and extracting the partial discharge statistical parameters of the oil paper insulation; by analyzing the change trends of seven statistical parameters, evaluating the insulation state of the oil paper insulation in the power device; and if NpSEC and Hn_Sk present a monotone increasing trend and the alfa, beta, Qmax, Hn_mean and Hqn_Kur present a monotone decreasing trend, judging that the oil paper insulation in the power device is in a deterioration state. The method can be used for forecasting the hazard degree of the partial discharge before the insulation has fault. The method can be used for preventing the insulation fault and reducing the fault possibility of the power device caused by insulation fault, has high accuracy and low dispersivity, is convenient to realize, and does not influence running of the power device.