In this paper, the main research achievements about the influence of solar activity on the climate and weather of the earth are introduced. Four key issues are discussed, which are: (1) solar activity and the energy budget of the earth system; (2) impact of solar activity on the earth’s climate, including climate change, greenhouse effect and volcanoes; (3) effect of solar activity on monsoon and weather; and (4) whether changes of solar activity will cause longterm cold climate of the earth. The elaboration to these issues is helpful for deeply understanding the fact and mechanism of the influence of solar activity on the climate and weather of the earth, and also the prospect of the possible changes of the earth’s climate in the future. Thus, I hope this paper could present a more comprehensive and profound understanding of the causes and driving forces of climate and weather change on the earth.