A date processing window software of source parameters for small earthquakes that is developed based on the MATAB platform and the brune model is designed. Its design reason, data processing and the usage of function modules in the visual software are introduced. Also some effects, produced by wave inelastic and heterogeneous attenuation, geometrical spreading, instrument and site response in the data processing, are analyzed. For easy use, in the design of the program the defaults of control parameters is set reasonably but keep the input interface for important control parameters.