SiC particle reinforced aluminum matrix composites are expected to be used as structural materials of the next generation space camera, due to their lightweight, high modulus, high thermal conductivity and low expansion coefficient. In this paper, several space environmental simulation tests, including the temperature cycling, the particle irradiation, the atomic oxygen irradiation and the vacuum-ultraviolet irradiation, are carried out for the SiCp/2009 aluminum matrix composites. The mechanical and physical properties of the composites are determined before and after the tests. The results show that before and after these space environment simulation tests, the yield strength, the tensile strength and the elastic modulus are changed no more than 2%, the average linear expansion coefficient is changed no more than 1×10-6℃-1, but the thermal conductivity and the specific heat capacity are each decreased by a maximum of 17% and 28%. Then a comparative study of different environmental effects on the mechanical and physical properties of the SiCp/2009 aluminum matrix composites and the internal mechanism of significant changes of the specific heat capacity and the thermal conductivity is briefly discussed. A model involving the stress affected zone (SAZ) around the SiC particles, the cumulative damages on the surface or inside the material during the irradiation tests and the inevitable voids inside the material because of the powder metallurgy process are proposed to explain the significant change of specific heat capacity and thermal conductivity before and after these space environment simulation tests.%碳化硅颗粒增强铝基复合材料（SiCp/Al）因具有轻质、高模量、高导热性能以及良好的尺寸稳定性等特点，有望成为新一代空间相机用结构材料。文章针对我国自主研发的新一代空间相机用碳化硅颗粒增强铝基复合材料开展了空间环境（包括高低温循环、粒子辐照、原子氧和真空紫外辐照）地面模拟试验以及湿热环境试验，并对试验前后材料的力学及热物理性能进行了比对测试。结果表明材料的屈服强度、抗拉强度、弹性模量的变化均不超过2%，平均线膨胀系数的变化不超过1×10-6℃-1，而比热容和导热系数则最高分别降低了17%和28%。之后对比研究了不同环境效应对材料性能的影响情况，并对比热容和导热系数发生明显变化的原因和内在机理进行了初步分析。
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