To evaluate and understand the jitter of the large aperture system,the concept of the jitter was firstly introduced.Then,the production and the influence factors of the jitter were discussed.For the thirty meter telescope tertiary mirror(TMT M3),the jitter reachs 0.1″RMS after calibration and 0.2 mas RMS after adaptive filtering.According to the requirement,the jitter of TMT M3 was analyzed,and the requirements and steps of the test were introduced.Lastly,the suppressing methods of the jitter were introduced from active isolation and control strategy.This work has guiding significance for the production and the suppression of the jitter of large aperture system.