The invention provides a comprehensive benefit analysis method and device for distributed photovoltaic access. The method comprises the steps of determining a power distribution parameter after distributed photovoltaic power distribution network access according to planning information of the distributed photovoltaic power distribution network access; calculating steady-state power flow one by one point in time within a preset time frame of the power distribution parameter, and determining electricity limiting quantity of each time point according to the steady-state power flow of each time point; judging whether the sum of electricity limiting quantities of all time points is larger than a preset value or not; calculating cost and benefit which are brought by the distributed photovoltaic power distribution network access when the sum of the electricity limiting quantities of all time points is smaller than or equal to the preset value; and determining comprehensive benefit of the distributed photovoltaic power distribution network access according to the cost and the benefit which are brought by the distributed photovoltaic the power distribution network access. By the method, the annual comprehensive benefit of the distributed photovoltaic the power distribution network access can be determined according to the planning information of the distributed photovoltaic the power distribution network access and annual 8,760-hour network running state, so that a scientific basis can be provided for distributed photovoltaic optimization and planning.