The invention discloses a television background wall projection device, relates to a background wall projection technology, and aims to solve the problem that a viewer cannot be immersed in a picturewhen watching a film due to poor relevancy between a television background wall atmosphere lamp and television content. An input video signal is converted into a high-definition image and a backgroundimage. The background image is displayed based on a projection area of a background wall, the high-definition image is displayed based on a liquid crystal screen, and contents displayed by the high-definition image and the background image are integrated. The television background wall has the advantages that background light is highly related to television content, a television and the background wall are integrated, viewing fatigue is relieved, and the most ideal effect of the background light is achieved.