Abstract: Now there are some prominent problems that water ratio rises quickly and the recovery is lower for some oilfields in Bohai Oilfield which has been put into production. And due to the limit of the platform life span, an offshore oilfield can be developed for only twenty years. So it is a difficult technology problem to be settled how to explore more oil as quickly as possible during the platform life span. Through analyzing the geology and reservoir of LD 10-1 Oilfield, the three dimension model has been matched, and then the design and optimization study of the slug concentration, injecting-polymer time, injection speed and injecting-polymer occasion of polymer flooding projects has been carried out, and finally the recommendatory projects have been given. The research results indicate that it is feasible to inject polymer early at LD 10-1 Oilfield, but should make sure that the injection pressure cannot exceed the pressure limit of platform pipelines.