Abstract: With the continuing growth of population and the decrease in arable lands, the global food crisis is becoming a serious problem for human beings. Therefore, further improving crop yield is important for our country to ensure food production safety. Photosynthesis is the material basis for crop yield, and the crop improvement focusing on increasing photosynthetic efficiency via modern breeding technologies is considered to be a new round of “Green revolution”. In this review, we summarize recent advances, current challenges, and applications in enhancing plant carbon assimilation through different approaches, including improving the carboxylation activity of Rubisco, introducing C₄ photosynthesis into C₃ crops, and reducing photorespiration. We also propose promising research emphasis and directions for imporving photosynthetic carbon assimilation of plants.