Internal stress of 1, 3, 5-triamino-2, 4, 6-trinitrobenzene (TATB) based polymer bonded explosive (PBX) is an important cause of its cracking and low stress damage. For verifying the feasibility of analyzing the internal stress of TATB based PBX by neutron diffraction, 2 kN dual leadscrew was mounted horizontally on the Residual Stress Neutron Diffractometer (RSND), and the internal stress alterations were measured by the in-situ neutron stress measurement technique under different load status. Results show that the(002) crustal plane (diffraction angle 29°) and(412) crustal plane (diffraction angle 75°) of TATB crystal can be used as a neutron stress observation surface. The changes in lattice spacing measured by neutron diffraction (lattice strain) is approximately linearly increased with the applied stress on it, and the lattice strain increases with the increase of stress. In the process of more complex in-situ compressive loading/unloading, the lattice strain result is basically consistent with the complex stress change process. The neutron diffraction signal intensity decreases exponentially with the path and the neutron diffraction depth is 6 mm.