We are developing a new image processing method named fluorescence emission ratio imaging(FERN), which relies on confocal system, can obtain Gaussian image and donut image at the same time, and then use image processing as the ratio to obtain super resolution images with significantly improved imaging resolution. This method can not only significantly improve the resolution, but also improve the resolution. It can also improve the image contrast and signal-to-noise ratio, by using traditional image processing methods, on the one hand can improve the processing speed, on the other hand can reduce the laser power so as to reduce the damage to biological tissues, but also for us to achieve high resolution imaging at low cost provides an alternative way.