The space truss structure is a large flexible space structure with complex dynamic characteristics such as low frequency, dense mode and nonlinearity. The intelligent identification of the service state of such structure is of great significance for deep space exploration of high orbit. For this reason, a method of deformation monitoring and inversion of space truss beam structure based on distributed fiber Bragg grating sensing technology is proposed in this paper. With the help of ANASYS finite element analysis method, the strain and displacement distribution characteristics of the beam structure under different loads are obtained by numerical simulation. The inversion algorithm of the deformation of truss beam structure is studied based on displacement algorithm, and the deflection information of space truss structure at different positions is obtained by calculation. On this basis, a distributed optical fiber deformation monitoring and inversion system for unilateral fixedsupported truss beams is constructed. The average relative error is about 2.4%. Finally, an error separation correction method for improving the inversion accuracy of beam structure deformation is proposed. After correction, the average relative error is reduced by 41.7%. The research results show that the proposed method has the advantages of high precision and good realtime performance. It can provide timely and accurate access to the structure of the space truss structure, and realize a powerful guarantee for adaptive adjustment and active control of the truss shape.