在小像差近似下，对偏置模式波前传感器进行了理论分析，明确了该传感器的适用条件，对比分析了3种信息提取方式和3种传感器信号输出方式的优劣。针对Zernike像差模式，数值模拟研究了传感器对单阶和多阶模式的响应特性。结果表明，畸变波前中与偏置模式相同或相关的模式之间有响应，但传感器对各阶Zernike模式的响应灵敏度不同，而且不相关模式的存在对传感器输出信号和灵敏度均有影响。

With approximation of little amplitude aberration modes, we present theoretical analysis and explore validate conditions of MBWFS. We also compare and analysis three ways of extracting information from intensity distribution in measurement plane and three definitions of sensor output signals, respectively. Performance difference of sensor to detect single and multiple modes is numerically studied in terms of Zernike aberration modes. The results show that, sensor sensitivity indicates aberration modes component and amplitude included in test wavefront, which are identical or relevant with those in bias-screen plate, but sensitivity to each Zernike aberration mode is different, and furthermore, irrelevant aberration modes can affect both output signals and sensitivity.