The utility model provides an engine room sealing door of a wind driven generator, which comprises a door substrate, a cover door, an air spring, oscillating bearings, a sealing strip, an arc-shaped handle, a hinge, a step and a handle lock. The door substrate is fixed on a support of a fan, the oscillating bearings are arranged at two ends of the air spring of the sealing door, the cover door is connected with the hinge through the air spring, the arc-shaped handle is mounted on the inner side of the engine room cover door, the step is located on the outer side of the engine room cover door, the sealing strip is installed on the periphery of the cover door, and the handle lock is mounted at the front edge of the engine room cover door. The engine room sealing door has the advantages of fine sealing effect, simple structure, safe use and the like, is particularly used for forced air cooling type wind driven generators, and can effectively cool motors and isolate impurities such as blown sand, dust and the like in natural environments.