Under the framework of the Paris Agreement,technology sharing and support from developed countries is one of the main requests for the conditional reduction targets of many developing countries. This study introduced a technology transfer mode into the integrated assessment model named CIECIA to study the global warming mitigation and carbon reductions under international technology transfer. The results show that technology transfer has significant carbon reduction and global warming mitigation effects. Low carbon technology transfer among developed countries has remarkable reduction potential,and its main barrier is the patent protection regimes. The developing countries with lower knowledge capital stocks and R&D capabilities spend more time imitating advanced technologies and thus are more sensitive to the improvement of R&D acceleration. The carbon reductions of developed countries are shocked by the withdrawal of the United States from the Paris Agreement,whereas the chain reactions that would worsen the technology transfer environment have more negative impacts on the carbon reductions of developing countries. China should improve its R&D input to enhance its technological learning capability in the short term. The active involvements in the international climate negotiations to achieve low carbon technology sharing mechanism is also important for China,as it is the institutional foundation for its carbon reductions by technology transfer in the long term.