扫描补偿系统是3DLIF水体测量系统中实现大尺寸平面激光等光程扫描的关键部分，决定了平面激光光束在流体水槽中的定位精度；系统3 000 mm长的光程和500 mm宽的光源使定位精度难以保证。针对该问题，分析了扫描补偿系统中可能存在的误差因素和各项因素之间的影响关系，建立了相关误差模型并进行仿真分析，对得到的误差数据进行了多项式拟合，拟合结果显示，棱镜制造角差和平面反射镜绕z轴的俯仰为影响位置误差的主要因素；为了减小误差，进一步分析拟合结果，得到了两项因素之间的关系表达式，提出了以仿真结果指导装调来减小误差的方法。最终仿真结果显示，通过该方法使平面激光在水槽中的位置误差可以从0.618 mm减小到0.103 mm。

The scanning compensation system is a key part of 3DLIF water measurement system to realize optical path scanning such as large-size planar laser,which determines positioning accuracy of planar laser beam in the fluid sink.This 3DLIF water measurement system has a long optical path length of 3 000 mm and a 500 mm wide light source, which makes it difficult to guarantee positioning accuracy.In order to solve this problem,influence factors of error factors and various factors in scanning compensation system are analyzed.Relevant error model is established and simulation analysis is carried out.The obtained error data are fitted by polynomial fitting and fitting result shows the angle between prism manufacturing and pitch of plane mirror around z axis are main factors that affect position error.In order to reduce the error, fitting result is further analyzed,and the relationship expression between two factors is obtained.Final simulation results show that position error of planar laser in the sink can be reduced from 0.618 mm to 0.103 mm by this method.