In order to study the relationship between dislocation configuration and grain refinement in materials treated by laser shock processing, 690 high-strength steel was impact-strengthened by pulsed laser. The scanning electron microscopy, transmission electron microscopy and high resolution transmission electron microscopy images of the sample treated by laser shock processing were obtained using scanning electron microscopy and transmission electron microscopy. The inverse fast Fourier transform was performed on the high resolution transmission electron microscopy image, and a grain refinement model of 690 high strength steel treated by laser shock processing was established from the perspective of dislocation configuration. The results show that after the 690 high-strength steel was loaded by laser shock with a power density of 5.09 GW/cm², the internal dislocations of the material are proliferated and the surface grains are refined, with grain size ranging between 80 nm and 200 nm (cross section). The precipitation phase maintains a semi-coherent relationship with the matrix, and many defects such as edge dislocations, dislocation couples and extended dislocations are distributed in the matrix, among which the dislocation couples are formed by the screw dislocation motion with cut order. The geometrical dislocation interfaces' extension and intersection divides the original large crystal grains into fine grains, which consists of dislocations, extended dislocations, vacancies, etc.The grain refinement model of 690 high strength steel treated by laser shock processing can describe the grain refinement process dominated by the dislocation movement of 690 high strength steel.