Amidst concerns from both Chinese and Anglo-American scholars regarding the deployment of technical investigative measures, questions have emerged about their potential misuse and the resulting impact on judicial procedure fairness, which encompasses procedural participation, equality, transparency, rationality, timeliness, and finality. This study explores procedural fairness issues in China’s criminal justice system by focusing on applying technical investigative measures in drug-related cases. We have gathered a sample of 800 verdicts of drug-related criminal cases with 1134 defendants from China Judgments Online. Employing logistic regression analysis, we investigated the influence of extra-legal and legal factors on applying technical investigative measures. Our research reveals that these factors significantly impact the utilization of technical investigative measures. Variables such as the defendant’s occupation, education, domicile, and ethnicity substantially influence the decision to deploy technical investigations. Furthermore, factors like the defendant’s crime type, severity, involvement in co-offending, and prior criminal records also affect the application of these measures. The results indicate that investigative agencies consider certain extra-legal factors when applying technical investigative measures that may result in potential misuse and consequently may affect the fairness of China’s judicial procedures. This study holds significant potential to inform and catalyze reforms within China’s criminal justice system.