Non-contributory social pension system, also known as social pension, was born almost at the same time as contributory pension system. However, its development has been relatively lagging behind. Before the 1990s, the popularity of social pension in developing countries lagged farther behind than that in developed countries. Based on the global social pension data of Help Age International, this study, based on literature review, analyzed the development trend, causes resulting in its rise, and poverty reduction effects of non-contributory social pension in developing countries since the 1990s. Combined with the experience of implementing the social pension in developing countries, the current paper puts forward suggestions to the future reform and improvement of China's old-age insurance system for both urban and rural residents. Firstly, appropriate system models are selected according to the national conditions. Secondly, we should pay attention to the long-term sustainability of the system and gradually improve the security based on the principle of continuous and gradual progress. Finally, the negative incentive effect of the social pension should be reduced through reasonable system design.