Targeted poverty alleviation is a new strategy of poverty alleviation put forward in the light of former extensive mode, which aims to improve the efficiency of poverty alleviation and practice social justice. The poor elderly population is the main part of the poor. To reduce the elderly poverty with low cost and high efficiency, it is necessary to rely more on social security system's institutional behavior rather than non—institutional behavior and depend more on market power rather than administrative power. The establishment and improvement of the “ generalized +preferential” model of social security system which is compatible with the stage of social development in China will help to achieve “ targeted poverty alleviation” and promote social efficiency and equity.