The invention discloses a projection picture control method of a
projector, a remote controller, the
projector and a
projection system, and relates to the technical field of
multimedia. The method comprises the following steps: the remote controller modulates and encodes light emitted by a
light source of the remote controller, and projects a
light spot for indicating a control action on a projection picture to the projection picture of the
projector. And the projector obtains the
light spot on the projection picture, projects a cursor used for indicating the control action on the projection picture on the projection picture, and controls the projection picture according to the control action. Compared with a method that a user operates a
light pen to realize projection and is easily influenced by natural light or environmental factors, the method provided by the invention has the advantages that the light spots emitted by the remote controller on the projection picture are acquired through the projector, the projection picture for controlling the projector is indicated based on the light spots, and the cursor is projected onto the projection picture again. Due to the fact that the cursor is emitted by the projector, the cursor can be visually and accurately displayed on the projection picture, the control action is presented on the projection picture, and the display effect of the projection picture is improved.