The invention discloses a method for calculating a critical multi-infeed interaction factor in consideration of direct current change. The method comprises the steps of determining a to-be-detected multi-infeed alternating current and direct current system and acquiring a multi-infeed alternating current and direct current system network, a network parameter, a component model and a model parameter to generate load flow calculation data; calculating the load flow calculation data by use of a load flow calculation method to obtain an operational parameter of the multi-infeed direct current system; and calculating the critical multi-infeed interaction factor in consideration of the direct current change among inverter stations.