The invention discloses a method and a system for in-situ measurement of the short-circuit capacity of a power grid based on non-fault disturbance. The method comprises the following steps: putting inor removing reactive power compensation equipment at a common access point of the power grid to produce non-fault disturbance on the power grid; acquiring the total active power and total reactive power of load at the common access point before disturbance; determining the vector difference of a voltage at the common access point of the power grid before and after disturbance; acquiring the effective value of the voltage at the common access point before disturbance; acquiring the capacity of the reactive power compensation equipment; and determining the short-circuit capacity of the common access point of the power grid according to the total active power, the total reactive power, the vector difference of the voltage, the effective value of the voltage and the capacity of the reactive power compensation equipment. Through adoption of the method and the system for in-situ measurement of the short-circuit capacity of the power grid based on non-fault disturbance provided by the invention, on-line measurement of the short-circuit capacity of the public access point of the power grid can be realized. Moreover, the method and the system have the characteristic of high measurement accuracy.