This paper detailedly proves an important character of a kind of flying saucer that it can equivalent fly without the consideration of the effect of sideslip,because it has unique geometry shape.

• 由于一类碟式飞行器具有独特的几何外形结构,详细证明了其侧滑飞行可以等效为无侧滑飞行的性质,根据这一性质,其侧滑飞行气动数据可以由无侧滑飞行的气动数据折算得到。