The embodiment of the invention provides an image data processing method and an image data processing device. In the embodiment of the invention, a second terminal uses frame sequence coding for original 3D image data, thus, data size of the obtained 3D image coded data is relatively low, consequently, the 3D image coded data is free from high speed transmission in a process of being transmitted from a server to a first terminal, and by low speed transmission, the first terminal also can be enabled to smoothly play a 3D video with high resolution ratio, so, even bandwidth between the server and the first terminal is relatively low, the first terminal cannot be influenced in playing the 3D video smoothly with high resolution ratio, thus, reduction of watching experience of users can be avoided. Secondly, the server simultaneously stores 2D image data codes and 3D image data codes, thus, personalized requirements of different users also can be considered.