An instrument usually is installed at the distal end of a continuum surgical robot to perform specific tasks. The driving wire of the instrument needs to pass through the central channel of the continuum robot. And force perception of the continuum robot is often lacking. Based on this application background, a novel fiber Bragg grating (FBG)-based 3-D force sensor is proposed. This sensor consists of an axial force perceptive zone and a radial force perceptive zone. Four optical fibers with dual FBG nodes are arranged for the sensor. Thanks to the novel arrangement of FBGs, one central channel is retained to arrange the driving wire of the instrument. A novel force perceptive model is established through the temperature decoupling algorithms and Bernoulli–Euler beam theory. Calibration experiments show that the proposed sensor can achieve a resolution of 1.9, 2.4, and 9.8 mN for ${F_{x}},{F_{y}}$ , and ${F_{z}}$ , respectively. Dynamic performance and temperature decoupling algorithms show that the proposed FBG sensor can accurately realize 3-D force perception.