An image encryption method based on a weed model belongs to the field of information encryption. The facts that divulgence of confidential information of image product content rises increasingly, computing power increases, hacker attack ability increases, and the duplication and propagation of digital images are convenient and fast, bring new challenges to digital image security. Most of present image encryption methods which have low security or low efficiency are far from satisfactory. According to the method, interactive image pixels are seen as grain seedlings, pixels added to the interactive image are seen as weeds, and the pixels are added to the interactive image through a certain rules to conceal the interactive image information and thus the image content is protected. The innovational content of the invention are: combined with digital image features, concepts such as weeds and crops are defined, and the weed model is established; a novel image encryption method is designed on the basis of the weed model. Experimental results show that the method is easy to realize, has good encryption effect, and can guarantees safe and reliable transmission of images in the network platform.