A projection system relates to the field of display technologies, and includes a projection unit, a screen unit, an outer frame, and a support structure component. The support structure component is configured to securely connect the screen unit to the outer frame. The support structure component is located on a light incident side of the screen unit. The support structure component includes a light transmission part and at least one connecting part. The light transmission part is securely connected to the screen unit. The light transmission part is configured to enable light rays emitted by the projection unit and irradiating the light transmission part to pass through. The at least one connecting part is located out of propagation paths of light rays emitted by the projection unit. The at least one connecting part is configured to securely connect the light transmission part to the outer frame.