The invention provides an operation risk assessment method and apparatus of a power distribution network containing a distributed power supply. The method comprises the following steps: firstly, calculating fault probabilities of a distribution line under different weather types and the fault probabilities of the distributed power supply under different weather types and operation service lives; then, simulating the operation state of the power distribution network according to the fault probabilities of the distribution line and the distributed power supply by using a pre-constructed distributed power supply force output model; and finally assessing the operation risk of the power distribution network according to the simulation result. According to the operation risk assessment method and apparatus provided by the invention, the type of the distributed power supply considered, and the operation risk assessment accuracy of the power distribution network is improved. The respective fault probabilities of the distribution line, and a photovoltaic power generation system, a draught fan and a gas turbine in the distributed power supply are calculated, the fault probabilities of the distribution line and the distributed power supply can be accurately reflected via comprehensive consideration, so that the operation risk assessment accuracy of the power distribution network is ensured.