In order to obtain a demulsifier suitable for the produced emulsion of WZ11-4 oilfield，A series of polyethers originated from amine initiator was prepared and the effects of sequence of PEO and PPO segments，branch number and PEO content in the polyether demulsifier as well as the solvents on demulsification efficiency were tested. It was found that the diblock polyether had higher demulsification efficiency than that of triblock polyether；the demulsification efficiency increased with the number of branches of the demulsifiers；and there was an optimum PEO content，being of about 25%，at which the polyether exhibited the best demulsification. In addition， the synergism effect between aromatic solvent and polyether demulsifier giving improved demulsification was also found. As compared with polyether dissolved in 95% alcohol，the same polyether dissolved in xylene has much faster dehydration velocity. The industrial two-block polyether demulsifier HYP-105 with PEO content of about 25% that originated from tetraethylenepentamine showed almost the same effect as the incumbent imported one，and could meet the application requirements.