A non-metal catalytic system consisting of dual functional alcohol oxygen anions as active centers and triethylboron (TEB) as monomer activator was reported in the article. It can effectively catalyze the anionic ring-opening polymerization of CO2 and ethylene oxide (EO) to synthesize polyethylene carbonate/polyethylene oxide (PEC/PEO) copolymers. Meanwhile, the aim of green synthesis of PEC/PEO with dual hydroxyl end groups and tunable carbonate contents (10%~99%) can be achieved in the way of the effective regulation of EO activity by directly controlling the amounts of TEB in the system. The hydrolysis properties of the copolymers were also preliminarily studied, confirming that the copolymers could be completely hydrolyzed into polyether segments with different chain lengths.