A data reading method, wherein the data reading method comprises: receiving, by a first control node, a reading message forwarded by a data switching device, wherein the reading message is used to instruct to read first data, and the reading message is sent by a second control node to the data switching device and then forwarded by the data switching device to other control nodes other than the second control node in a node group; and if a data status identifier of the first data in a first storage node is a valid identifier, reading, by the first control node, the first data from the first storage node, resetting the data status identifier of the first data in the first storage node from the valid identifier to an undefined identifier, recording a destination control node of the first data in the first storage node as the second control node, and sending the read first data to the data switching device, so that the data switching device forwards the read first data to the second control node, wherein the valid identifier indicates that the first data on the first storage node is available, and the undefined identifier indicates that the destination control node provides currently latest first data; wherein the node group comprises a storage node that is in a multiprocessor network and that stores the first data, a maximum of one storage node in the node group stores the first data whose data status identifier is a valid identifier, and the data status identifier of the first data stored in the storage node in the node group is reset to the valid identifier when the storage node in the node group stores available first data; the node group further comprises a control node connected to the storage node in the node group; the control node is configured to exercise read/write control on the connected storage node, comprising setting a data status identifier for the first data stored in the connected storage node; the first control node is a control node in the node group, and the first storage node is a storage node that is in the node group and that is connected to the first control node. receiving, by a first control node, a reading message forwarded by a data switching device, wherein the reading message is used to instruct to read first data, and the reading message is sent by a second control node to the data switching device and then forwarded by the data switching device to other control nodes other than the second control node in a node group; and if a data status identifier of the first data in a first storage node is a valid identifier, reading, by the first control node, the first data from the first storage node, resetting the data status identifier of the first data in the first storage node from the valid identifier to an undefined identifier, recording a destination control node of the first data in the first storage node as the second control node, and sending the read first data to the data switching device, so that the data switching device forwards the read first data to the second control node, wherein the valid identifier indicates that the first data on the first storage node is available, and the undefined identifier indicates that the destination control node provides currently latest first data; wherein the node group comprises a storage node that is in a multiprocessor network and that stores the first data, a maximum of one storage node in the node group stores the first data whose data status identifier is a valid identifier, and the data status identifier of the first data stored in the storage node in the node group is reset to the valid identifier when the storage node in the node group stores available first data; the node group further comprises a control node connected to the storage node in the node group; the control node is configured to exercise read/write control on the connected storage node, comprising setting a data status identifier for the first data stored in the connected storage node; the first control node is a control node in the node group, and the first storage node is a storage node that is in the node group and that is connected to the first control node.