The invention relates to a self-lifting type marine drilling platform lifting device and method. The device comprises a main floating pile, an auxiliary floating pile, a locking mechanism between a platform and a pile leg, a locking mechanism between the auxiliary floating pile and the pile leg and a locking mechanism between the main floating pile and the pile leg. The locking mechanism between the platform and the pile leg comprises a middle sliding block, an upper sliding block, a lower sliding block, a frame and a power driving device. The locking mechanism between the auxiliary floating pile and the pile leg comprises a frame, an auxiliary floating pile upper pin, a lower telescopic block, an auxiliary floating pile pin, a spring plate, a force limiting device, a spring pushing-pulling system and a limiting pin. By extracting or injecting seawater in main floating pile and the auxiliary floating pile, gravity force is changed, buoyancy is used, the locking mechanisms are matched, and up-down moving and locking of the platform and the pile leg are achieved. Lifting is stable and continuous, locking is flexible, and damage is not easy.