For the current status that the edge drop detector of cold tandem rolling mill can only control the rolling thickness deviation less than 10 μm at C15 (distance of 15 mm from edge) of cold rolled steel strip and meanwhile cannot avoid the bulging defects generated in the other positions, a new optimization method of dual-slope tapered work roll contour was proposed to strengthen the edge control and reduce the rolling defects. Then, through in-depth analysis on the contour structure Stand 1 (S1) dual-slope tapered work roll and edge drop control mechanism, the rolling force model for edge drop control of wide and narrow steel strips was established, and the contour of work roll was modified several times based on the numerical simulation results. Furthermore, the new dual-slope tapered work roll after optimized design was verified by rolling experiments on the industrial rolling site. The results show that the optimized S1 dual-slope tapered work roll can be used in conjunction with the existing Level 1 (LV1) edge drop control system, which can give full play to the edge drop control capability of tapered work roll and effectively avoid the bulging defects of cold rolled steel strip during rolling process.