Abstract: The orbital dynamics of dust particles ejected from the surface of 162173 Ryugu and escaping into interplanetary space within 1 000 years, mean motion resonance of dust particles with Earth and close encounters between dust particles and Earth were analyzed using direct numerical simulations. The effects of non-gravitational perturbations (solar radiation pressure, Poynting-Robertson drag and solar wind drag) on the long-term orbital evolution of dust particles were investigated. In the spatial region where dust particles move, the evolution of the semi-major axis, eccentricity and orbital inclination of the dust particles in the 3:4 and 4:5 mean motion resonances with the Earth were analyzed. That is, the semi-major axis of the dust particles showed periodic oscillations, the eccentricity showed periodic changes and slightly increased, and the orbital inclination showed a periodic downward trend. The number of close encounters between dust particles and the Earth was counted and analyzed. It is found that the number of close encounters reaches a maximum value within a period of 400 to 500 years, and the dust particles will not collide with the Earth within 1 000 years.