Based on the constructed wake vortex decaying model,movement model and encountering model,the concept of object-oriented(OO) is applied to develop the Dynamic Calculating tool for the Spacing of Wake Vortex.The tool includes the calculating module of flow field induced by leading aircraft,the encountering and reacting module for the following aircraft,and the module for calculating the spacing of wake vortex.The real-time and efficient calculation of wake vortex spacing can be implemented by using the aircraft parameters,meteorological data,and aerodrome data.And also,the spacing for the pair of B777-200 and B737-800 is calculated by this tool for trialing purpose.