In various kinds of testing systems, large-capacity data file is common. File processing method based on C,
C++ and MFC was introduced in this paper. In the light of functions in Win32 API, reading, data decomposing and analysis
method of large-capacity data file were presented. According to practical requirement, the data processing software is
designed. By experimental verification and practical data testing, the processing method posed in this paper can analyze
and process large-capacity data file effectively. The processing method presented in this paper has been employed in several
space measurement projects successfully and obtained satisfactory analysis result, which provided the reliable basis
for relational tests and experiments.