Construction of block copolymers is a practical method for modifying the properties of CO2-based polycarbonates (CO2-PCs) in order to meet specific needs. Herein, we report a well-defined single-site beta-diiminate zinc complex 1 equipped with the capacities of coordination copolymerization of CO2/epoxide and reversible addition fragmentation chain transfer (RAFT) polymerization of vinyl monomers. Complex 1 is specifically designed to possess a 3-(benzylthiocarbonothioylthio)propionate (BSTP) initiating group, which enables the controlled ring-opening copolymerization of epoxides and CO2, leaving a polycarbonate with BSTP functional group at the end of the chain. The end-capped BSTP allows direct chain extension via living RAFT polymerization, thus providing a robust construct various CO2-based block copolymers in one pot via a tandem catalysis strategy. The structure of 1 is established by single-crystal X-ray diffraction as well as H-1 and C-13 NMR By utilizing 1, a wide range of CO2-based block copolymers including poly(cyclohexene carbonate)-block-poly(2-(dimethylamino)ethyl methacrylate) (PCHC-b-PDMAEMA), poly(cyclohexene carbonate)-block-polystyrene (PCHC-b-PS), and poly(cyclohexene carbonate)-block-poly(N-isopropylacrylamide) (PCHC-bPNIPAM) with controlled molecular weight and compositions are prepared. These block copolymers are fully characterized by DSC, H-1 NMR, and C-13 NMR spectroscopy. Especially, a thermoresponsive PCHC-b-PNIPAM copolymer is for the first time synthesized as a functional nanomaterial. The complex and catalytic process provided here offers a straightforward catalytic access to CO2-based block copolymers.