本文分别用ＡＳＥＤ—ＭＯ和ＤＶ—Ｘα方法对氧在理想的Ｓｉ（１００）面以及用ＤＶ－Ｘα方法对氧在重构的Ｓｉ（１００）面吸附进行了研究，对不同吸附位的计算结果表明：①氧原子在Ｓｉ（１００）面以（短）桥位吸附最稳定，认为氧在硅表面是解离吸附，且Ｏ与Ｓｉ形成Ｓｉ－Ｓｉ吸附态；②ＤＶ—ｘα方法对表面吸附及催化剂性质的研究具有较好的精确性和适用性；③当氧在硅表面暴露量较少时，其吸附为原子和氧分子共存。 In this paper, the adsorption of oxygen on reconstructed Si (100) surface was investigated by using the ASED-MO and DV-Xα methods on the ideal Si (100) surface and the DV-Xα method respectively. The results show that: (1) The oxygen atoms are most stable at the (short) bridge site of Si (100) surface, and the oxygen is dissociatively adsorbed on the silicon surface and O and Si form Si-Si adsorbed state; The catalytic properties of the study has good accuracy and applicability; ③ when the oxygen in the silicon surface less exposure, the adsorption of atoms and oxygen molecules coexist.