A data transmission method includes: capturing, by a virtual reality host, a portion of an image to be transmitted in a preset area to obtain a first image, and compressing, by the virtual reality host, a portion of the image to be transmitted in a display area to obtain a second image, wherein the preset area is a portion of the display area (S101); transmitting, by the virtual reality host, the first image and the second image to a virtual reality apparatus in a certain order (S102); receiving the first image and the second image by the virtual reality apparatus (S103); stretching the second image by the virtual reality apparatus, and merging the first image with a stretched second image by the virtual reality apparatus to obtain an image to be displayed (S104); and displaying the image to be displayed by the virtual reality apparatus (S105).