In order to improve the efficiency and accuracy of loss calculation for HVDC converter station， a loss calculation application software is developed using Visual Basic， based on loss calculation models in the IEC 61803 Standard， with the function of parameter correction and save， loss calculation and results output. It is applied to calculate converter station losses in the Guizhou—GuangdongⅡ HVDC system. The calculation program is proved to be accurate， fast， convenient and general， and can also function well for other HVDC converter stations.