IEC 61970 international standard which published by the International Electrotechnical Commission is abided by many power system software. Its application and implementation protects the Power Supply Companies' investments well. However, among the existing power system computation software, it is almost impossible to read the real-time data from other software's kernel. And this approach will cause some unexpected hazards to data security. Considering to the data security, the author will give out a solution to solve this problem in this paper. That's to be the semi-offline data interface. From the running software which follows IEC61970 international standard, data of the grid will be exported to a fixed path folder according to a certain time interval. And then parse the data from the folder when it is needed in the second auxiliary software of power system dispatching. The parsed data, containing necessary information of the grid's structure, will be used for the calculating in the second software's sub-module. The whole idea of the interface has got the relevant application of engineering practice, and achieved good results.