Abstract： Abnormal uterine bleeding （AUB） associated with Mirena （levonorgestrel-releasing intrauterine system） insertion is the most common adverse reaction to Mirena，severely affecting women′s quality of life. Restraining excessiveness to acquire harmony is the fundamental regulatory mechanism for maintaining dynamic balance in nature. Under the guidance of this theory， this paper elaborates that the root cause of Mirena-induced AUB lies in the insufficiency of the kidney， spleen， and liver in their restraining functions， while the manifestation involves the invasion of pathogenic heat-toxin and obstruction of blood stasis，which become excessively harmful. Accordingly，it is proposed that traditional Chinese medicine （TCM） treatment should "pacify the excessiveness of the overacting revenge qi and support the insufficient qi to achieve harmony." That is，attention should be paid to invigorating the spleen qi， nourishing the kidney， and soothing the liver to consolidate the root by restoring the restraining-regulating function， while also addressing pathogenic heat-toxin and blood stasis to restrain the excessiveness and treat the manifestation. By restoring the dynamic balance of the body through the restraining-regulating relationship，the goal is to achieve a state of relative equilibrium of yin-yang，thereby regulating the menstrual cycle and stopping bleeding.