Abstract：Objective：To explore Ren Xianqing's experience in the treatment of Henoch Schonlein purpura with bleeding due to blood heat syndrome. Methods：The prescription information of 3 160 children was collected，and the data mining of the relationship between core drugs and drug compatibility was carried out by using Apriori algorithm and complex network analysis method. Results：The core prescriptions for the treatment of Henoch Schonlein purpura with bleeding due to blood heat syndrome were rehmannia glutinosa， peony bark， arnebia， salvia miltiorrhiza， dandelion， honeysuckle vine， scutellaria baicalensis，saponin thorn，coix seed and roasted licorice，aiming at clearing heat and cooling blood，promoting blood circulation and removing blood stasis. Among them，the commonly used compatibility of clearing heat and cooling blood is peony bark- rehmannia glutinosa- dandelion， arnebia- honeysuckle vine- rehmannia glutinosa， etc.， and the commonly used compatibility of clearing heat and cooling blood， promoting blood circulation and removing blood stasis is scutellaria baicalensis- dandelion- honeysuckle vine- rehmannia glutinosa- salvia miltiorrhiza. Conclusion： Through data mining， this paper summarizes the syndrome differentiation and treatment idea of Professor REN Xianqing， "clearing heat and cooling blood is the foundation， promoting blood circulation and removing blood stasis is the key， and regulating physique is the guarantee"， especially the core concept of "promoting blood circulation and removing blood stasis and preventing kidney damage" throughout the treatment， which provides a theoretical basis for popularizing the experience of famous and old traditional Chinese medicine and lays a foundation for further improving the clinical efficacy of traditional Chinese medicine.