Tertiary mirror (M3M) of thirty meter telescope (TMT) and its prototype reflector (M3MP) are elliptic reflector. Their support structure takes 18 points whiflletree. Telescope support optimization methods are reviewed in this paper. By using the multidisciplinary integrated optimization software ISight, the support points of M3MP are optimized. The SlopeRMS of M3MP′ s mirror surface error when the optical axis is vertical is selected as objective function. And the global optimization algorithm simulated annealing algorithm was used to optimize. Final surface error SlopeRMS is decreased 14.3% compared to the initial support points. The results show the effectiveness of optimization method.