Three-dimensional curve fitting and reconstruction of an intelligent structure shape were researched to implement the active monitoring for a high-performance aircraft structure shape. Firstly, the B-spline curve fitting method and recursive algorithm for coordinate fitting were introduced, and algorithm processes and implementation steps as well as numerical simulation analysis were presented. Then, a flexible structure model and its experimental environment were established, and visualization software was developed based on the Visual C++ and OpenGL technology. Furthermore, the curvature detection principle of the orthogonal distributed Fiber Bragg Grating(FBG) sensor array was demonstrated, subsequently, the three-dimensional space shape fitting and reconstruction of the experiment model structure were analyzed and verified. Finally, B-spline fitting algorithm and linear interpolation algorithm were adopted separately to construct a standard circle with the radius of 50 cm. Experimental results show that B-spline fitting algorithm has better graphical reconstruction effects comparing with linear interpolation algorithm, and its standard deviation is 40% that of linear interpolation.As the FBG intelligent flexible structure shows the better shape reconstruction and visualization, it verifies the high precision and low error characteristics of the B-spline algorithm.