Abstract: In view of characteristics of low illumination and low definition of image in distributed coding of coal mine underground video, an algorithm of side information generation of coal mine underground video sequence based on full search was proposed. The algorithm expanded key frames which have been decoded, analyzed and judged the mean square error function value of corresponding pixel of block of each reference frame during full search by threshold. It reserved motion vector below the threshold, and improved quality of side information generation. The theoretical analysis and simulation results show that the algorithm can realize generation of high-quality side information of coal mine underground video sequence, and provides foundation for distributed coding widely used in coal mine underground video surveillance and communication.