The invention discloses an image focusing measure implementation method based on direction statistical characteristics, and belongs to the technical field of image processing. The method comprises thefollowing steps: firstly, preprocessing an image, then partitioning the processed image, and calculating direction statistical characteristics of each sub-image to obtain statistical values of the corresponding sub-image in four directions; And the definition information of the sub-images is constructed through the statistical values in the four directions. and finally, solving the variance of aset formed by the definition information of all the sub-images, and taking the variance value as the focusing measure of the whole image. According to the method, image detail information is extractedby adopting an image blocking mode and direction statistical characteristics, the method has the advantages of being simple in principle and low in calculation complexity, meanwhile, through the implementation of the steps, the interference of noise on the image detail information is reduced, and particularly, the noise robustness under the low-contrast imaging condition is high. The method is suitable for a passive imaging system of the camera, and has high popularization and use values.