Common prosperity requires the common prosperity of all people. Solving the problem of relative poverty is a key difficulty in promoting common prosperity. Since the reform and opening up，the pattern of poverty in Beijing has continued to change，and solving the problem of relative poverty has been put on the agenda. From the strategic height of promoting common prosperity，we should find the path to solve the relative poverty problem，and the focus is to explore the establishment of a sound triple mechanism. The first is the organizational leadership mechanism of “party committee leadership，government leadership，multiple participation，and result evaluation”. The second is operational mechanisms of “policy guidance and guarantee，active monitoring and discovery，joint assistance with materials and services，and equal basic public services”. The third is endogenous motivational mechanisms of “livelihood development，poverty prevention，intergenerational interruption，social integration”.