Abstract：Objective：To analyze the medication rules of principal prescriptions for anorectal diseases recorded in Wai Ke Zheng Zong（ Orthodox Lineage of External Medicine） using Python. Methods：All formulas related to anorectal diseases were screened from Wai Ke Zheng Zong，and the constituent herbs were extracted. Data analysis was performed using PyCharm Community Edition 2021.2.3. Frequency statistics of herbs， properties and flavors， and meridian tropisms were calculated. Spearman correlation analysis， association rule analysis， and hierarchical cluster analysis were conducted， and the results were visualized. Results： A total of 52 prescriptions for anorectal diseases were identified， involving 117 herbal drugs with a cumulative frequency of 430 times. The top 15 most frequently used herbs in descending order were Angelica sinensis， Glycyrrhizae Radix， Chuanxiong Rhizoma， Astragali Radix， Atractylodis Macrocephalae Rhizoma， Ginseng Radix， Coptidis Rhizoma， Paeoniae Radix Alba， Rhei Radix et Rhizoma， Scutellariae Radix， Poria， Rehmanniae Radix Praeparata， Citri Reticulatae Pericarpium， Forsythiae Fructus， and Rehmanniae Radix. The predominant herb flavors were bitter， sweet， and acrid； the properties were mainly warm and cold；meridian distribution was primarily spleen，liver，and heart meridians；main efficacies were tonifying， heat-clearing， and blood-activating. Spearman correlation analysis yielded 10 core herb pairs such as Ginseng Radix-Atractylodis Macrocephalae Rhizoma. Association rule analysis generated 20 three-item association rules， e.g.， Chuanxiong Rhizoma-Glycyrrhizae Radix-Angelica sinensis. Systematic cluster analysis produced three initial clusters which were integrated into two categories， namely， spleen-strengthening， qi-tonifying， and bloodnourishing herbs， and heat-clearing， fire-purging， and dampness-dispelling herbs. Conclusion： The treatment of anorectal diseases in Wai Ke Zheng Zong is based on the three therapeutic principles of elimination， support， and tonification，with an integrated system emphasizing both "spleen-strengthening，qi-tonifying，and blood-nourishing" and "heat-clearing， fire-purging， and dampness-dispelling" to address root and branch simultaneously. The core concept of differentiation and treatment is "taking the spleen-stomach as the foundation，and regulating qi and blood in concert."