Long horizontal well usually encounters with different layers with varies reservoir characteristics and the damage degree is different in the horizontal section. Also, the distribution of damage zone is no homogeneous and it’s difficult to deliver acid uniformly. The problem of acid delivery in the long horizontal well can be effectively solved by the use of temporary chemical diverting acidizing technology. Based on the chemical diverting acidizing mechanism and considering acid flowing in the formation and wellbore as an interactional unite, chemical diverting numerical model was developed and solved through coinciding reservoir and wellbore and the process of horizontal well temporary chemical diverting acidizing technology was modeled. The result shows that it can provide theoretical guidance for horizontal well chemical diverting technology.