With the rapid development of smart healthcare, humanoid robotics, and virtual and augmented reality technologies, optic fiber force sensors attract increasing attention due to their advantages of high sensitivity, high precision, rapid response, and immunity to electromagnetic interference. To address the environmental disturbance susceptibility of traditional optical fiber force sensors, we propose a cascaded sensitivity enhancement scheme based on the vernier effect using tapered optical fibers. A TOF sensor with a 65 mm taper length is fabricated, achieving a sensitivity of -2.08 nm/N under pressures ranging from 0 to 1 N. After cascading this sensor with a second tapered optical fiber, the maximum sensitivity increased to 10.11 nm/N. The results indicate that the vernier effect can effectively enhance force sensitivity. This high sensitivity exhibits significant application potential in fields such as smart healthcare and robotic tactile sensing.