The invention discloses a method for combined focusing of microscope lenses of different magnification based on image textures. The method includes the steps of using a low-magnification objective lens; initializing the position of the z axis; allowing an objective table move downwards for N steps, calculating the image definition of the camera at equal intervals, recording the maximum definitionand the z axis position where the maximum definition is located, moving the objective table to 90% of the position where the current position and the maximum definition are located, determining the moving step length of the objective table according to the image definition at the moment, repeating the steps until the definition reaches a certain error range of the maximum definition, dividing theeffective area on a slide glass into m * n blocks, calculating the definition value of each sub-block, moving the center of the sub-block with the largest definition value to the position right belowthe objective lens, replacing the objective lens with a high-magnification objective lens, repeating the focusing process and finally completing the combined focusing. According to the method, the problem of being stuck in local extreme value in an existing focusing method is effectively solved, and the problem that focusing cannot be achieved due to the fact that no targets exist in the field ofview is solved.