Planned as a whole by the military, the current military pension system has some shortcoming such as narrow insurance coverage, weak link-up between systems, low pension level in practice, overloaded finance, low-efficient fund management. In order to plan the pension system by the nation and insure military pension right, a new military pension system should be constructed including pooling accounts, individual accounts and annuity accounts. The transition cost of military pension system comes from explicitation of recessive debt under the system of present military pension system. By system dynamics approach, the transition cost of military pension system is estimated. The results show that by the end of 2090, the transition costs is fully explicit；both transition cost of "old" and "middle aged" appear a high-to-low trend； from 2035 to 2065, the cost reaches a peak value. The pooling accounts capital accumulation buffer and the changes of population age structure, financial payment risks caused by system transition can be well dispersed, and the reform will not bring enormous pressure on government finances. Therefore, the direction of social overall planning for pension insurance should be held on and the reform of military pension system should be positively promoted.