利用可见光波段的同步光直接成像对北京正负电子对撞机二期工程(BEPCⅡ)储存环束流的横向截面尺寸进行了测量，对可见光直接成像方法的光路搭建注意事项进行了详细说明，并详细阐述了此测量方法对光路放大倍数的精确测量及过程，同时对可能产生的随机误差和系统误差提出了处理方法，利用点扩散函数(PSF)对成像过程中产生的衍射误差进行了处理，这些处理方法对其他测量系统如X射线小孔成像也适用，并将测量结果与可见光空间干涉方法测量结果进行了对比，且符合很好。

The beam profile measurement of BEPCⅡ storage ring by visible synchrotron light imaging method is illustrated. The optics details and precise measurement of the magnification by the method are elaborated. Approaches for possible arbitrary error and system errors are suggested, such as dealing with the diffraction error by using point spread function (PSF) deconvolution, which are also available for other similar measurement like X-ray pinhole camera. The measurement results agree well with the spatial interferometer method data.