There are several shortcomings, such as poor succession and low efficiency, when BPA transient calculation program is called by some advanced application systems in EMS through tradition interface. In order to solve these shortcomings, an interface designed for calling BPA transient calculation program quickly and effectively is proposed. Through setting unified BPA transient calculation program interface file interaction standard, the shortcoming of poor succession is solved. According to the features of the advanced application systems in EMS, a method to call the BPA transient calculation program quickly and effectively is designed to call the BPA interface more quickly and effectively. A test case is done in Guangdong Power Grid of China to call the BPA transient calculation program interface using the fine operational rules online automatic discovery system. The results show that the designed interface for calling BPA transient calculation program has good succession and high efficiency, can call the BPA transient calculation program more quickly and effectively.