With the continuous increase in the penetration rate of distributed photovoltaics （PV） in the distribution network，the impact of power electronic equipment represented by grid-connected inverters on the power grid is increasing，and the risk of wide-band oscillation in the power grid is intensifying.However，few existing studies have proposed wide-band oscillation stability criteria to meet the safe operation of grid-connected distributed PV with a high penetration rate，so that effective suppression measures cannot be taken.In view of this，an analysis method for wide-band oscillation under grid-connected distributed PV with a high penetration rate based on the equivalent model is proposed.Firstly，the distributed PV cluster division and aggregation modeling methods are studied，and the equivalent model of the distribution network is established.Secondly，the wide-band oscillation analysis is carried out based on the equivalent model，and the analysis method of wide-band oscillation under the grid-connected distributed PV with high penetration rate is proposed.Then，the impedance characteristics of the equivalent model are obtained by the frequency sweep method，and the wide-band oscillation analysis is carried out.Finally，the IEEE 33 detailed model and equivalent model are built based on Simulink，and the simulation research is carried out in the equivalent model of the actual 110 kV regional distribution network；the effectiveness of the wide-band oscillation analysis method proposed in this paper is verified by comparing the simulation results of the impedance characteristics of different models.