By taking an xenon lamp and Light Emitting Diodes(LEDs) as luminescence media, an integrating sphere solar spectrum simulator was proposed to improve the matching precision of solar spectra. The Simulated Annealing (SA) algorithm was introduced to study spectrum matching technique, and the mechanical structures and control systems of LED module and xenon lamp module were designed. The LEDs were positioned in an annular manner, driven by a constant current and controlled by a multi-computer communication system. A cut-off filter and a programmable attenuator were mounted in the xenon lamp module, a filter was used to cut off the infrared spectrum of xenon lamp and an attenuator was used to vary the incidence radiant flux of xenon lamp entered in the integrating sphere. The simulation experiment indicates that 53 Epitex LEDs and the xenon lamp could simulate the AM 1.5 standard solar spectra successfully, and the average relative error is 5.67%. The mismatching error, irradiance uniformity and the irradiance instability were analyzed and discussed, and they all has the potential of performing better than ±3%.