Abstract: Lightning overvoltage is one of the risk sources that threatens the safe operation of a power system. However, the statistical laws of intrusive lightning overvoltages in substations are not clear at present. Thus, it is difficult to provide basic data for the study of discharge characteristics of insulation dielectrics, resulting in over-design or under-design of insulation coordination. Based on the measured intrusive lightning overvoltages from the 10 kV side of a substation, the statistical distribution laws of amplitude and waveform parameters are studied in this paper. It is found that there is a significant difference between the intrusive lightning waveform and the IEC standard of 1.2/50 μs double exponential waveform. According to the waveform characteristics of intrusive lightning overvoltages in the substation, the statistical characteristics of overvoltage amplitude, wave front time, dominant oscillating frequency and damping factors are proposed and the probability density distribution is identified by the Kolmogorov-Smirnov(KS) test method. The statistical data show that the amplitude of intrusive lightning overvoltage measured from the 10 kV side of the substation is distributed among 12, 42 kV, and its probability density obeys the Burr distribution. The distribution of wave front time is within 8.3, 167.0 μs and its cumulative probability density obeys the BiDoseResp distribution. The dominant oscillating frequency is distributed among 2.08, 22.22 kHz with an average value of 5.84 kHz, and 99.28% of the oscillating frequency is less than 15 kHz. The probability density of the dominant oscillating frequency obeys the Generalized Pareto distribution. The damping factor of the waveform is distributed among the range of 0.01, 0.90 with an average value of 0.39, and its probability density obeys the Beta distribution. The research results can provide basic data for the study of insulation characteristics, insulation coordination, supporting the data layer construction of the internet of things in power systems.