CCTF Working Group on Two-Way Satellite Time and Frequency Transfer is one of the most important working groups under CCTF of CIPM, whose members mainly participate in the national time-frequency lab of international satellite two-way comparison, aiming to coordinate the link cooperation of world’s various two-way labs, organize the adjustment of global various two-way links so as to decrease the uncertainty, and promote the development of new technology of satellite two-way comparison and jointly time transmit of other time transmit technologies with high precision etc., playing a very important role on improving the precision and stability of international atomic time.