The present invention provides an intelligent cloud platform-based active power distribution network power supply capability index online calculation method. The method is implemented by a power supply capability index online calculation system, and comprises the steps of (1) using an intelligent cloud platform to determine the power distribution network nodes in which the charging equipment powerand the distributed photovoltaic power generation power are injected in an active power distribution network; (2) using the intelligent cloud platform to determine the charging power value of a powerdistribution network node DNi at the moment t; (3) using the intelligent cloud platform to determine the distributed photovoltaic power generation power value injected at the moment t of the power distribution network node DNi; (4) sending the calculation data of the power distribution network node; (5) calculating the power supply capability indexes of the active power distribution network nodes at the moment t via a power supply company DMS system; (6) calculating a power supply capability comprehensive index. The present invention provides a new method for the power supply capability index online calculation on the condition that the large-scale charging equipment access the active power distribution network.