<p>During TBM tunneling, the friction between the rock mass and the cutters generates substantial heat, resulting in cutterhead temperature variations. In this study, the cutterhead working status monitoring system was installed on open-type TBMs in three tunnel sections to enable real-time cutterhead temperature acquisition. Combined with recorded rock mass conditions, a database was established. By analyzing the temperature data obtained from multiple monitoring points on the cutterhead, it was found that the temperature in the outer region was higher than that in the center of the cutterhead. As the cutterhead diameter increased, the cumulative heat effect intensified. The cutterhead temperature during TBM tunneling decreased as the rock mass quality became worse. The temperature between Class III and Class IV rock masses showed a particularly significant drop. Through logistic regression analysis, the temperature threshold for distinguishing Class I–III from Class IV–V rock mass groups was determined to be 23.5 ℃. The temperature difference (Δ<i>T</i>) within a single tunneling cycle further indicated that in Class IV and V rock masses, the percentage of tunneling cycles with a negative Δ<i>T</i> increased significantly. Tunneling cycles with a large positive Δ<i>T</i> were associated with abnormal cutter wear, while those with a negative Δ<i>T</i> were correlated with groundwater conditions. Thus, the corresponding warning threshold of Δ<i>T</i> was set to 4 °C for abnormally worn cutters and −&#xa0;2 °C for groundwater conditions. The results can help identify adverse geological conditions and avoid construction accidents.</p>