The proportion of ultra-high water-cut horizontal wells in offshore oilfields is relatively high.? And due to the problem of oil-water co-plugging, the success rate of water plugging is very low. In order to improve the success rate of water plugging in horizontal wells, a reservoir temporary plugging protection system was prepared using Span80, AES and CAB as emulsifiers, and the 17 million molecular weight salt-resistant polymer was used as stabilizer.The types and concentrations of emulsifiers and stabilizers in the temporary plugging protection system were determined through molecular dynamics simulation and laboratory experiments. The optimal preparation condition for the temporary plugging protection system were: 3% emulsifier ( Span80:AES:CAB = 8:1:1 ) + 0.2% polymer ( 17 million salt-resistant polymer ). The performance of the temporary plugging protection system was tested by liquid separation time method and one-dimensional sand filling tube model. The results showed that this system had good emulsification stability that no drninage phenomenon within 4 days, oil-water selectivity and permeability recovery ability under high temperature and high salt conditions. And the temporary plugging protection system effectively realized the liquid flow diversion under the permeability difference was less than 4 and the injection rate was 2.0mL/min. In general, the temporary plugging protection effect of the oil layer is remarkable. This study provides theoretical basis and technical support for reservoir protection in offshore oil horizontal well water plugging operation.