A fiber tapering technique is used to optimize a central symmetry multicore fiber that has a large core spacing. The tapered fiber has the characteristics of a strong evanescent field and high sensing sensitivity; however, it is difficult to use as a bending sensor because of its poor flexibility. This paper proposes a flexible structure design so that the optimized tapered fiber can be used as a bending sensor. The transmission spectrum of the optimized multicore optical fiber sensor is analyzed using supermode coupling theory. In addition, the bending sensing characteristics of the sensor are experimentally studied. The experimental results indicate that there is a good linear relationship between the interference fringes and bending curvature. The sensitivity of the optimized tapered fiber sensor is 2.90 nm/m^-1.