Agriculture plant disease and insect pests is varied and tremendously harmful, so experts are needed to diagnose. But experts can’t have the energy and time to the field for the majority of farmers to guide, they can only get the image through remote. However, agriculture plant disease and insect pests image is rich in detail, while transmission bandwidth and storage is limited, it is necessary to compress image to make sure of image quality. This paper proposes an improved method based on Jacquin theory to reduce coding time. Encoded sub block is classified into detailed block and non-detailed block, so we can reduce the encoding time. Experimental results show that, for the agriculture plant disease and insect pests image which is rich in detail, the number of encoded blocks reduces to 31.45 % and the encoding time reduces to 32.9 % of the original one.