Abstract: To the challenge of high degree irregularity,complex gravity field and relatively high degree of physical parameters uncertainty of small celestial bodies,the impact of dynamic parameters uncertainty is analyzed,based on the approximate linearized analytical solution of the small celestial body landing dynamic equations.A calibrating method is used to compensate the errors brought in by linearization.And the sensitivity equations ofspacecraft trajectories to dynamic parameters are established.Taking the asteroid Eros 433 as an example,the impact of the uncertainty of the mass,rotation rate and gravitational potential coefficients of the target body on the spacecraft landing trajectory,the initial state of the spacecraft and the thrust acceleration are analyzed elaborately.Mathematical simulation shows that for this selected target body,the thrust acceleration disturbance is the primary factor of such impact,and the initial state of the spacecraft the secondary one.And the impact of other parameters are relatively small