The invention provides a stability analysis method, device and implementation device of a photovoltaic power generation system. The method comprises the steps of acquiring a system parameter of the photovoltaic power generation system, wherein the system parameter comprises an equivalent current source and equivalent impedance of the photovoltaic power generation system; building an electrical model, connected with the photovoltaic power generation system, of an inverter group, wherein the inverter group comprises a plurality of sub-inverters in the electrical model, and the plurality of sub-inverters are connected to the photovoltaic power generation system in a parallel mode; building a mathematical model of the electrical model according to the electrical model and preset basic parameters of the sub-inverters; inputting preset disturbance of the equivalent current source to the mathematical model to obtain a current changing curve in the electrical model under disturbance; and obtaining a stability analysis result of the photovoltaic power generation system according to an extreme value of the current changing curve and a preset change threshold. By the method, the accuracy of astability analysis mode of the photovoltaic power generation system is improved, and the analysis efficiency is improved.