The utility model provides a calculating system device for the benchmark generating capacity of a wind turbine generator. The calculating system device comprises an anemograph installed on the wind turbine generator, an anemometer tower for measuring the wind speed and the wind direction, a data acquisition server, a data processing server and multiple communication assemblies. The anemograph and the anemometer tower are in signal connection with the data acquisition server through the communication assemblies, and the data acquisition server is in signal connection with the data processing server through the communication assemblies. By the adoption of the structural design, after the data processing server receives wind resource information of the data acquisition server, according to the IEC standard, data of the anemometer tower are combined with 10-minute average wind speed data measured by the anemograph, and in contrast of a wind turbine generator power curve given by a manufacturer, the benchmark generating capacity of the wind turbine generator is calculated. The benchmark generating capacity of the wind turbine generator can be reliably counted, the generating efficiency of the wind turbine generator is monitored by referring to the data, and therefore the real performance of the wind turbine generator is judged.