Abstract:As a new type of solar cells, Perovskite solar cells (PSCs) have attracted worldwide attention due to their rapidly improved photoelectric conversion efficiency in a short time. Hole transporting materials (HTM) is an important part of perovskite solar cells. Design and synthesis of low-cost, efficient and stable HTM play a great role in the development of PSCs. This review summarizes the molecular engineering of organic small molecule HTM based on linear Donor-Acceptor-Donor (D-A-D) configuration and their application in PSCs since 2009. Meanwhile, we highlight the effect of molecular structure on the power conversion efficiency (PCE) and device stability of PSCs. Based on above result, the feature research interest on D-A-D type HTM are presented.