Abstract: In order to meet the needs for standard light source of photoelectric detectors during calibration and correction, using the integrating sphere technology, it was designed that a button battery-powered portable LED uniform light source with diffuse reflection. The assembly drawings, main parts 3D drawing and circuit diagram of the light source were given and detailed described. By analyzing the gray value of each pixel of charge coupled device (CCD) photograph at light source outlet using Matlab, it was found that the light intensity evenness was 95.1% in ϕ14 mm range of light outlet. Besides, through the analysis of light intensity uniformity and diffuse reflection of light outlet by Ocean Optics USB 2000+ spectrometer, it was found that the light intensity dropped by 2.93% and 6.30%, respectively, at two positions along the light outlet radial direction, compared with the central position.The light intensity of central position was suppressed by 6.30% when the flat of light outlet was rotated 10°.Test analysis results show that the light source has a good uniformity and diffuse reflection, the design has some practical and reference values for photoelectric detectors calibration.