Scholars have long demonstrated the effectiveness of using visual representations to aid non-native speakers in learning Mandarin tone. Among these methods, presenting pitch contours visually has proven to be the most intuitive and efficient. However, the variability of pitch contours in continuous speech, influenced by coarticulation, poses challenges for learners to follow accurately. To address this issue, we propose a method to normalize pitch contours, mitigating the effects of coarticulation and prosodic phrasing. Experimental results show that subjects can identify the class of tone by looking at the representation proposed in this study and evaluating the quality of the tones of the syllables pronounced by the speakers visually. In addition, our approach can present the mispronunciation with the contours of the relative pitch of the syllables. We believe that our method offers more comprehensive feedback to learners compared to relying solely on a tone recognition model for pronunciation evaluation.