The herb pair is the simple and exquisite experience summary accumulated by generations of traditional Chinese medicine (TCM) experts in the process of long-term herbal prescription for curing diseases. Although it is only a combination of two herbs, it is cleverly matched and properly proportioned, which can well interpret TCM characteristics of "great combination and artful application". Moreover, the herb pair is an intermediate point between single herb and several TCM formulae, which implicates certain regularity and some connotation of many TCM formulae for diagnosis and treatment based on an overall analysis of the illness and the patient's condition. Our team has long been focusing on the complexity of drug interactions and the diversity of TCM components to carry out systematic research on herb pair by using modern scientific and technological knowledge and approaches. As results, a series of modern research approaches and strategies formed for the compatibility effect and bio-active components of the herb pair. By representing the principles and application characteristics of these approaches, this paper provides important support for elucidating scientific connotation of compatibility regularity of herb pairs and application of formulae optimization, as well as explorative ideas and approaches for modern research on other herb pairs.