With the growth of electricity demand and the enhancement of power grid network, it may be necessary to consider the contribution of the dynamic load to the short-circuit current for the more realistic assessment of the circuit breaker breaking capacity and dynamic stability. The PSS/E BKDY module is improved by applying the IPLAN language embedded in PSS/E to call PSS/E API routines and PSS/E API batch commands so as to set PSS/E data cards automatically according to user defined rules and calculations. The short-circuit current of a metropolitan power system is calculated with both the improved PSS/E BKDY module and PSS/E transient stability module and the results from those two module are very close. Therefore the improved PSS/E BKDY module is verified to be able to calculate the short-circuit current decay with dynamic load considered. This work is supported by National High-tech R & D Program of China (No. 2011AA05A106).