The work aims to study a blueberry freshness indicator made of blueberry anthocyanins and apply it in blueberry packaging to indicate the freshness change of blueberry during transportation and storage. The color difference of freshness indicator during the storage of blueberry was taken as the test index to study the factors affecting the color difference. First of all, the influence of the peel concentration, filtrate pH value and filter paper dipping time on the indicator color difference was studied by single factor experiment. Then, the optimum technological conditions were optimized by orthogonal test. The results of orthogonal test showed that the optimum technological conditions of blueberry freshness indicator were as follows: the peel mass concentration was 4 g/(100 mL), the pH value of filtrate was 12, and the dipping time of filter paper was 1.5 min. The color difference of freshness indicator under these conditions was 54.69. The blueberry freshness indicator whose optimal production process is obtained in the orthogonal test method has clear color boundaries, and it is a practical blueberry packaging label.