Abstract: Weizhou A oilfield is a continental complex fault block oilfield. The second member of Liushagang reservoir in development horizon is thin interbedded reservoir with complex sand body connectivity. In order to implement the connectivity between wells, the study of interference well testing has been carried out. Based on the analysis of pressure response speed and width-thickness ratio of sand body, an empirical formula for pressure response of interference well testing has been established, and a quantitative characterization method for the connectivity of thin interbedded reservoirs has been proposed. It is considered that the product of the proportion of vertical unconnected layers and the difference of signal receiving time and pressure coefficient between wells is a power function. Connectivity analysis of 5 production wells in the middle block of the oilfield has made, and the connection relationship between the planar well point and the vertical layer is obtained. Guided the next four adjustment wells deployment and injectionproduction relationship optimization measures, which can improve block recovery by 9.2%. It also provides a solution for the connectivity analysis of thin interbedded reservoirs in similar complex fault block oilfields.