An image scaling method, comprising the steps of: determining a distribution direction of main objects comprising persons, faces of persons or areas of rich textures in a source image through detection of the source image, wherein the distribution direction is one of horizontal and vertical; scaling the source image to a target image through a nonlinear scaling method according to the determined distribution direction of the main objects in the source image, wherein the nonlinear scaling method employs a scaling direction perpendicular to the determined distribution direction of the main objects in the source image; wherein the determining the distribution direction of the main objects comprises: detecting the source image through face detection method, edge detection method, or entropy coding method; if the face detection method is performed, detecting the distribution of the faces of persons in the source image, obtaining the distribution direction of the main objects through the distribution direction of the persons and the symmetry information; if the edge detection method is performed, calculating the edge distribution of the source image, identifying the areas of rich textures in the source image, determining the distribution direction of the main objects; and if the entropy coding method is performed, detecting a direction with an even distribution of the main objects in the source image, and determining the distribution direction of the main objects in the source image. determining a distribution direction of main objects comprising persons, faces of persons or areas of rich textures in a source image through detection of the source image, wherein the distribution direction is one of horizontal and vertical; scaling the source image to a target image through a nonlinear scaling method according to the determined distribution direction of the main objects in the source image, wherein the nonlinear scaling method employs a scaling direction perpendicular to the determined distribution direction of the main objects in the source image; wherein the determining the distribution direction of the main objects comprises: detecting the source image through face detection method, edge detection method, or entropy coding method; if the face detection method is performed, detecting the distribution of the faces of persons in the source image, obtaining the distribution direction of the main objects through the distribution direction of the persons and the symmetry information; if the edge detection method is performed, calculating the edge distribution of the source image, identifying the areas of rich textures in the source image, determining the distribution direction of the main objects; and if the entropy coding method is performed, detecting a direction with an even distribution of the main objects in the source image, and determining the distribution direction of the main objects in the source image. detecting the source image through face detection method, edge detection method, or entropy coding method; if the face detection method is performed, detecting the distribution of the faces of persons in the source image, obtaining the distribution direction of the main objects through the distribution direction of the persons and the symmetry information; if the edge detection method is performed, calculating the edge distribution of the source image, identifying the areas of rich textures in the source image, determining the distribution direction of the main objects; and if the entropy coding method is performed, detecting a direction with an even distribution of the main objects in the source image, and determining the distribution direction of the main objects in the source image.