A method for processing wood by a wood processing system comprising: a wood conveying device having a longitudinal direction along one direction in the horizontal direction, the wood conveying device conveying wood along the longitudinal direction; a multi-axis processing machine arranged on one side in the longitudinal direction of the wood conveying device, the multi-axis processing machine including a spindle capable of being attached with a first tool, and a spindle moving device having two or more linear axes (421, 422) perpendicular to one another and two or more rotational axes (423, 424) for moving the spindle; at least one multi-articulated robot arranged along the wood conveying device on the other side in the longitudinal direction of the wood conveying device, the at least one multi-articulated robot including a wrist capable of being attached with a tool unit including a second tool, and an arm having six or more rotational axes for moving the wrist; characterized in that the wood processing system comprises as well: a photographing unit; and an image processing unit; the method comprising the steps: photographing the wood with the photographing unit; detecting with the image processing unit positional coordinates of the wood by image-processing a photographed image photographed by the photographing unit comprising: detecting with the image processing unit a grain or a knot of the wood by image-processing the photographed image of the wood; performing a processing operation in accordance with the position of the grain or the knot of the wood by the multi-axis processing machine or the at least one multi-articulated robot, wherein the processing operation includes changing the position of the wood to be cut and changing the feed speed of the tool. a wood conveying device having a longitudinal direction along one direction in the horizontal direction, the wood conveying device conveying wood along the longitudinal direction; a multi-axis processing machine arranged on one side in the longitudinal direction of the wood conveying device, the multi-axis processing machine including a spindle capable of being attached with a first tool, and a spindle moving device having two or more linear axes (421, 422) perpendicular to one another and two or more rotational axes (423, 424) for moving the spindle; at least one multi-articulated robot arranged along the wood conveying device on the other side in the longitudinal direction of the wood conveying device, the at least one multi-articulated robot including a wrist capable of being attached with a tool unit including a second tool, and an arm having six or more rotational axes for moving the wrist; characterized in that the wood processing system comprises as well: a photographing unit; and an image processing unit; photographing the wood with the photographing unit; detecting with the image processing unit positional coordinates of the wood by image-processing a photographed image photographed by the photographing unit comprising: detecting with the image processing unit a grain or a knot of the wood by image-processing the photographed image of the wood; performing a processing operation in accordance with the position of the grain or the knot of the wood by the multi-axis processing machine or the at least one multi-articulated robot, wherein the processing operation includes changing the position of the wood to be cut and changing the feed speed of the tool. detecting with the image processing unit a grain or a knot of the wood by image-processing the photographed image of the wood; performing a processing operation in accordance with the position of the grain or the knot of the wood by the multi-axis processing machine or the at least one multi-articulated robot, wherein the processing operation includes changing the position of the wood to be cut and changing the feed speed of the tool.