Based on conceptualizing Chinese online populism as a grassroots discourse and operationalizing it in terms of people-centrist and anti-elitist dimensions, we developed an automated semantic text analysis method for analyzing Chinese online populist discourse both quantitatively and qualitatively. First, we introduced semantic role labeling to reformulate the original text into semantic triplets. Second, we created a Chinese populism dictionary containing terms signifying "the people," "elites," and "popular sovereignty." Third, we developed a rule-based method to recognize populist discourse automatically. The automated semantic text analysis method can capture a great deal of qualitative information throughout this process for further analysis. The validation test showed that the automated semantic text analysis method performed satisfactorily (accuracy > 0.9). This method not only creates a broadly applicable and reliable tool for studying Chinese online populism, but it also contributes to the literature on how populism manifests in various cultural and political contexts, expanding the possibilities of populism research globally.