Photobleaching induced by excitation light limits the application of confocal microscopy for long-time observation of biological samples. A new imaging approach, controllable light exposure-confocal microscopy (CLE-CM), is proposed. CLE-CM has two thresholds decided through pre-experiments and detects the feedback of sample pixel value at set intervals. The feedback is compared with upper and lower thresholds. By spatially controlling the light-exposure time of objective pixel according to the results of comparison, CLE-CM exploits fluorescent information in a more efficient way and reduces photobleaching without decreasing image quality. Two scan series of 11 successive CLE-CM images and standard confocal images show that, CLE-CM reduces 52.62% of photobleaching in bovine pulmonary artery endothelial (BPAE) cells compared with standard confocal at the 11th image. The effect of bleaching attenuation depends on the fluorophore distribution. CLE-CM decreases photobleaching markedly through the reduction of excitation-light dose, and increases the number of good-quality images that can be captured continuously by confocal microscope.