Du Peng and Li Long pointed out in the first issue of Journal of Renmin University of China in 2021 that China's population is ushering in a "great change not seen in a century" of negative growth in scale. Judging from the wavy and phased growth process of the scale and proportion of China's elderly population, 2035 and 2050 will be the key time nodes of population aging. By 2050, the overall size of the elderly population is about 480 million, with a corresponding proportion of more than 35%; the size of the elderly population aged 80 and above will exceed 100 million, accounting for 20%. To fully grasp the development trend of population aging, on the one hand, we should grasp its wavy characteristics and phased characteristics, and change from the acute thinking of aging work to the forward-looking thinking of aging work; on the other hand, we should also focus on its more prominent gender structure change and particularly critical age structure change, and change from the single dimensional approach to aging problem to the systematic approach to aging problem.