Abstract: There are torsion components of multi rotation degree of freedom in the optics mechanism system disturbed by specifically environment of vibration. The disturbances induce deflection jitter of directional angle of the beam emitted by the system, result in the centralization degree of radiant energy falling in dynamic spread form. With adopting means of probability and statistics, the representative testing result of the beam random jittering is analyzed by dualistic statistics. On the basis that factual amplitude distribution of jitter is close to characteristic of the normal law, it is discussed from cumulative radiant effects the distribution characteristic of energy deposition on the radiated surface by directional beam and the approximate evaluation means about energy diffusion extent