A method and a device for controlling projection of a wearable apparatus, and a wearable apparatus are provided. With the projection method, a 3D profile of the object as projection screen is acquired by a 3D acquisition device disposed on the wearable apparatus; coordinates of vertices of the projection area on the object as projection screen are determined according to the acquired 3D profile of the object as projection screen; a projection plane is determined according to the determined coordinates of vertices; and the projection is controlled according to the angle between the projection plane and the center line of the projection view angle of the projection component, the distance between the geometrical center of the projection plane and the projection component and the 3D profile of the object as projection screen such that the projection picture projected by the projection component is clearly and steadily projection displayed in the projection area on the object as projection screen.