Abstract: Non-fault disturbance-based method and system for measuring short-circuit capacity of a power grid on site including: connecting or disconnecting a reactive compensation device to or from a power grid point of common coupling, to generate a disturbance on a power grid; obtaining total active power and total reactive power of a load of the point of common coupling before the disturbance; determining a vector difference between a voltage of the power grid point of common coupling before the disturbance and a voltage of the power grid point of common coupling after the disturbance; obtaining a voltage effective value of the power grid point of common coupling before the disturbance; obtaining a capacity of the reactive compensation device; and determining a short-circuit capacity of the point of common coupling according to total active power, total reactive power, vector difference between voltages, voltage effective value, and capacity of the reactive compensation device.