Abstract: The technology of geologic simulation is developed from one or two dimensions to three dimensions.The data that need to be analyzed and processed increase geminately even exponentially.Although the speed of data analyzing and processing is improving rapidly with the developing of computer technology, it wastes time and money to analyze and process those huge amount of data by ordinary programming with common computer languages.With its powerful function of data analysis and processing and simulation, MathCAD is necessary and feasible to be used in geologic simulation.This paper briefly introduces the function of MathCAD and its applications in data analyzing and data processing of geologic simulation.