Amidst the global popularity of music programs, the music attainment of audiences has kept enhancing, thus setting higher bars on intonation for music performers. For this reason, correct intonation is essential for both instrumentalists and singers. Despite various kinds of tuners and tuning software on the market today, software and system capable of both tone tuning and correction are still in short supply. Therefore, a system that corrects intonation of musical instruments and people’s voice is designed and implemented herein. The system delivers pitch detection, intonation judgment and correction for simple notes. By collecting audio via NI myDAQ and analyzing the frequency spectrum of the audio through LabVIEW on PC, it realizes pitch detection and judges intonation by comparing the audio with the standard tone, and utilizes the pitch shifting algorithm to correct intonation. Test results show that the system can accurately detect pitch and judge intonation, with a desirable correction effect. The system described herein provides references for tuning of simple musical instruments and guidance for training of singers.