The present disclosure discloses a 3D display method and a display device, relates to the field of display technologies, and can improve the 3D display effects of a Vertical Alignment (VA) liquid crystal display. The 3D display method comprises the steps of: acquiring effective grayscale of an image to be displayed; acquiring compensation data for brightness of the image to be displayed based on the effective grayscale thereof; and driving, during display of the image, a backlight source based on the compensation data for brightness, so as to compensate for brightness of the image to be displayed. The 3D display method is especially suitable for a VA display device. The present disclosure can be used in a display device, such as a liquid crystal television, a liquid crystal display, a mobile phone, a tablet personal computer, etc.