The fourth Plenary Session of the 19th Central Committee of the Communist Party of China proposed to “establish a longterm mechanism to solve relative poverty”, making “relative poverty” become an active hot word. Absolute poverty and relative poverty can be understood from two perspectives: one is the two ways of defining and measuring poverty, the other is the two ideas of formulating antipoverty policies. As a policy concept, absolute poverty and relative poverty are different in some ways, but they are interrelated and permeated into each other. The further development of relative poverty has created a divergent thinking and inclusive atmosphere, leading to some new concepts such as multidimensional poverty and multidimensional poverty index. In the process of modern poverty research, absolute poverty, relative poverty and multidimensional poverty are the responses of policy ideas and action strategies with the change of external environment. Now the problem is how to implement them into policies and actions.