Abstract: The TYSC-3Q digital well logging instrument is the main equipment to exactly explore in the coal industry and nuclear industry. In the process of data collection, it uses parallel interface to communicate with PC. Malfunction appeared frequently in actual exploring. Based on the analysis of the principle and exsisting problems of the TYSC-3Q digital well logging instument, the sequence of data communicating with PC was studied deeply, and reformed scheme was proposed by using SCM technology, in which the original interface card was replaced by RS232 serial interface.