Maternity insurance as an important part of social security can promote women’s employment，social harmony，social protection and family stability. On February 12，2014，Beijing Population and Family Planning Ordinance amendment formally adopted Selective Two-Child Policy and into the implementation phase. In this paper，Single family fertility desires of Beijing and based on its influencing factors to analysis two-child policy has influence on maternity insurance and comment related content of the Social Insurance Law，in addition to suggest recommendations to improve fertility insurance policy.