Aiming at the problem of three-dimensional shape reconstruction of multi-core optical fiber, a three-dimensional shape reconstruction method based on helical multi-core optical fiber and Bishop frame is proposed. The principle of 3D position reconstruction method based on HMCF and Bishop frame was analyzed. The Fiber Bragg grating (FBG) array sensing was used to calculate the strain of each fiber core through spectral drift. The core curvature and torsion angle solution were calculated according to the node section strain relationship model. Four shape reconstruction experiments were carried out, and the maximum absolute error of 3D reconstruction was 3.11mm. The experimental results show that the shape reconstruction method based on Bishop-HMCF can realize 3D shape reconstruction, which has important research significance and application value in the end positioning and navigation of flexible mechanism.