The Statistical test and analysis methodologies are applied to Operational Test and Evaluation (OT&E) by analyzing the mechanism of OT&E. The step of Operational Test and analysis (OT&A) based on Statistical test and analysis methodologies are concluded and the related theory of OT&A is discussed. An OT&A case of AirtoAir Missile are studied to verify the proposed method. Both the science and stringency of OT&E are improved by applying statistical test and analysis methodologies.