推导了相干照明下衍射受限螺旋相衬成像系统的成像公式,总结了影响螺旋相衬法成像效果的螺旋相位板参数,包括中心尺寸、整体尺寸以及台阶数。详细研究了各参数对螺旋相衬成像系统性能的影响,提出了各参数的合理取值范围,并通过实验验证了其正确性。所采用的计算方法,不仅可以用于研究螺旋相位板的设计,而且对于其他空间滤波器的设计同样具有参考价值。 The imaging formulas of diffraction limited spiral phase contrast imaging system under coherent illumination are derived. Parameters of spiral phase plate, including the center size, the overall size and the number of steps, which affect the imaging performance of spiral phase contrast method are summarized. The influence of each parameter on the performance of spiral phase contrast imaging system is studied in detail. The reasonable range of each parameter is put forward. The correctness of the proposed method is verified by experiments. The calculation method adopted can not only be used to study the design of spiral phase plate, but also has reference value for the design of other spatial filters.