In the process of optical dynamic target work, under the effort of the arm of dynamic target, the mirror needs to do
circular motion, additional accelerated motion and uniform motion. The maximum acceleration is 10°/s<sup>2</sup> and the
maximum velocity is 30°/s. In this paper, we mostly analyze the dynamic deformation of a 600 mm honeycomb
light-weight mirror of a certain dynamic target. Using the FEA (finite element analysis) method, first of all, we analyze
the deformation of the light-weight mirror induced in gravity at different position; later, the dynamic deformation of
light-weight mirror is analyzed in detailed. The analysis results indicate that, when the maximum acceleration is 10°/s<sup>2</sup>
and the maximum velocity is 30°/s, the centripetal force is 5% of the gravity at the equal mass, and the dynamic
deformation of the mirror is 6.1% of the deformation induced by gravity.