The invention provides a wind power plant equivalent modeling method with the low voltage ride through characteristic considered. The method comprises the steps that action situations of Crowbars of all DFIG units are judged according to action area curves of the Crowbars of the DFIG units and the operation state of each unit in a wind power plant in the voltage dropping period, grouping is conducted on the units according to the action situations of the Crowbars, then, the units belonging to the same groups are combined by the adoption of the weighting volumetric method, parallel connection processing is conducted on current collection network impedance of the units belonging to the same groups, and equivalent models of two units of the wind power plant are obtained, wherein one equivalent unit represents the group of units where the Crowbars act during a power grid fault, the other equivalent unit represents the group of units where the Crowbars cannot act during the power grid fault and the equivalent input wind speed of the two equivalent units is solved by the adoption of the wind speed cubic weighting polymerization method. The invention further relates to a wind power plant equivalent modeling device with the low voltage ride through characteristic considered.