Marginal oil fields have the features of small reserves, poor economic performance, high cost, and difficult development. However, most of the offshore oil fields found in recent years are marginal oil fields. It is necessary to develop reusable facilities with small investment for such oil fields. Movable platforms have simple structure and light weight, and can realize installation without the need of large-scale installation vessels, thus leading to an investment saving. Besides, they can be moved to other similar oil fields for reuse. The main types, scope of applications and installation methods of movable platforms are introduced. The structure and scheme of a real application example in the development of marginal oil fields are described in detail.