A stitching label sending method, wherein the method comprises: receiving, by a controller, first label range information sent by an intermediate forwarding device or an intermediate forwarding node, wherein the first label range information indicates a first label range in a plurality of label ranges of the intermediate forwarding device or the intermediate forwarding node, the first label range indicates a label space block, the label space block includes one label or a plurality of labels which are used to select the stitching label; selecting, by the controller, a label from the first label range as the stitching label; and sending, by the controller, the stitching label and a first label stack corresponding to the stitching label to the intermediate forwarding device or the intermediate forwarding node, wherein the first label stack indicates a segment of label switched path starting from the intermediate forwarding device or the intermediate forwarding node, and wherein the segment of label switched path starting from the intermediate forwarding device or the intermediate forwarding node is a first label switched path; wherein before the receiving, by a controller, first label range information, the method further comprises: sending, by the controller, a label request message to the intermediate forwarding device or the intermediate forwarding node, wherein the label request message is used to request the first label range information; and wherein the controller stores second label range information, the second label range information indicates a second label range in the plurality of label ranges of the intermediate forwarding device or the intermediate forwarding node, and before the sending, by the controller, a label request message to the intermediate forwarding device or the intermediate forwarding node, the method further comprises: detecting, by the controller, that a quantity of available labels in the second label range is less than a first threshold, or a proportion of an available label in the second label range to all labels in the second label range is less than a second threshold, wherein the available label in the second label range refers to a label that is not selected as the stitching label in the second label range. receiving, by a controller, first label range information sent by an intermediate forwarding device or an intermediate forwarding node, wherein the first label range information indicates a first label range in a plurality of label ranges of the intermediate forwarding device or the intermediate forwarding node, the first label range indicates a label space block, the label space block includes one label or a plurality of labels which are used to select the stitching label; selecting, by the controller, a label from the first label range as the stitching label; and sending, by the controller, the stitching label and a first label stack corresponding to the stitching label to the intermediate forwarding device or the intermediate forwarding node, wherein the first label stack indicates a segment of label switched path starting from the intermediate forwarding device or the intermediate forwarding node, and wherein the segment of label switched path starting from the intermediate forwarding device or the intermediate forwarding node is a first label switched path; wherein before the receiving, by a controller, first label range information, the method further comprises: sending, by the controller, a label request message to the intermediate forwarding device or the intermediate forwarding node, wherein the label request message is used to request the first label range information; and wherein the controller stores second label range information, the second label range information indicates a second label range in the plurality of label ranges of the intermediate forwarding device or the intermediate forwarding node, and before the sending, by the controller, a label request message to the intermediate forwarding device or the intermediate forwarding node, the method further comprises: detecting, by the controller, that a quantity of available labels in the second label range is less than a first threshold, or a proportion of an available label in the second label range to all labels in the second label range is less than a second threshold, wherein the available label in the second label range refers to a label that is not selected as the stitching label in the second label range. sending, by the controller, a label request message to the intermediate forwarding device or the intermediate forwarding node, wherein the label request message is used to request the first label range information; and wherein the controller stores second label range information, the second label range information indicates a second label range in the plurality of label ranges of the intermediate forwarding device or the intermediate forwarding node, and before the sending, by the controller, a label request message to the intermediate forwarding device or the intermediate forwarding node, the method further comprises: detecting, by the controller, that a quantity of available labels in the second label range is less than a first threshold, or a proportion of an available label in the second label range to all labels in the second label range is less than a second threshold, wherein the available label in the second label range refers to a label that is not selected as the stitching label in the second label range.