A display apparatus and a displaying method thereof are provided. The display apparatus includes a transmissive display panel, a liquid crystal glass, a backlight module and a transparent polarizer film. The liquid crystal glass is disposed at a side of the transmissive display panel. The liquid crystal glass has a transparent state and an atomization state and is adapted to switch between the transparent state and the atomization state. The backlight module is disposed at a side of the liquid crystal glass away from the transmissive display panel. The backlight module includes a transparent light-guiding plate and at least one light bar. The liquid crystal glass is located between the transmissive display panel and the transparent light-guiding plate. The transparent polarizer film is disposed at a side of the transparent light-guiding plate away from the liquid crystal glass.