The invention provides an array micro-beam unit 
deflection angle measurement 
system, comprising an illumination 
light source, a condenser, a filter needle hole, a collimating 
system, a 
polarizer, a polarizing 
beam splitter, a one quarter wave plate, a fourier conversion 
system, a filter edge, a fourier reverse conversion system and a 
CCD camera; the light emitted by the illumination 
light source passes through the beam filter which consists of the condenser and the filter needle hole, is converted into parallel light by the collimating system, and is converted into a 
linearly polarized light beam by the 
polarizer; the 
linearly polarized light beam illuminates the array micro-beam by the reflection of the polarizing 
beam splitter and reaches the polarizing 
beam splitter again after being reflected by the array micro-beam; the linearly polarizing 
light beam passes through the one quarter wave plate between the polarizing beam splitter and the array micro-beam twice, with the 
phase change of Pi /  2; the imaging beam reflected by the array micro-beam can pierce the polarizing beam splitter and is imaged on the 
CCD camera after passing through a 4f 
filter system which consists of the fourier conversion system, the filter edge and the fourier reverse conversion system. By controlling the polarizing state of the illumination light, the array micro-beam unit 
deflection angle measurement system reduces the 
background noise of the measured 
signal, improves the 
signal-
noise-ratio of the system, and presents unique advantages.