The invention discloses an image processing method, a device and a mobile terminal based on a convolutional neural network, which are suitable for the execution in a mobile terminal with a graphic program interface, wherein the convolutional neural network comprises a plurality of processing layers and a plurality of data layers and the method comprises: inputting a to-be-processed image into the convolutional neural network as first data layers; for each data layer, according to the maximum pixel value and the minimum pixel value of the data layer, converting the various pixel values of the plurality of characteristic images in the data layer into texture data; according to the sizes, the numbers of the horizontal textures and longitudinal textures of the characteristic images, combining the plurality of characteristic images after being converted into the texture data to form a corresponding big texture that is saved; for each processing layer, converting the texture data in the big texture corresponding to the previous data layer connected thereto into the first data format; and invoking the graphic program interface to render the texture data corresponding to the processing layer to generate a plurality of characteristic images for a next data layer.