Abstract: The quality of the Global Navigation Satellite System (GNSS) observation data directly affects the accuracy and reliability of GNSS positioning. In order to obtain observation data of good quality, users usually use TEQC software to preprocess the data. Because TEQC is a command line software based on DOS system, it has some defects such as poor interaction and weak visualization function. At present, although there are third-party drawing tools such as QCVIEW, CF2PS and QC2SKY that can realize the drawing function, these tools no longer support the Compact3 format result files generated by TEQC after March 15, 2013. Therefore, this paper uses Python language to visually design the quality inspection module of TEQC, and compiles a quality visualization software TPP (TEQC Plot of Python). The software performance test and analysis show that the software can reflect the satellite quality check index at different time, azimuth and altitude angle.