This paper summarizes the current research and applications of oil field chemical additives in drilling fluids, completion fluids, and reservoir protection, and holds the view that the research and applications of the positive ion drilling and completion fluid system should be the development orientation in the future. For the development trend of oilfield chemical additives, it is, guided by new oilfield chemistry theory, to design molecules, develop new-style monomers, synthesize new types of polymers, and develop modified products of multifunctional natural polymers with environmental-amity.