A cluster data processing method using a cluster including at least two servers (a 0,...a n, 420) and a load balancing device (110, 410, 510), the method comprising: sending, by a requesting server in the cluster, a request for connection to an external server; receiving, from the external server, a response to the request for connection and, in response, establishing the connection between the requesting server in the cluster and the external server; sending a first data comprising a first controlling identity record from the requesting server in the cluster to the external server, wherein the first controlling identity record includes a unique identity and a control information, wherein the control information contains server location information identifying a desired server in the cluster; disconnecting, by the requesting server in the cluster, the connection between the requesting server in the cluster and the external server; receiving, by the load balancing device in the cluster, a request for a new network connection from the external server; upon establishing the network connection, receiving a second data at the load balancing device in the cluster from the external server, wherein the second data is obtained by processing the first data by the external server and contains a second controlling identity record including the unique identity and the control information received by the external server in the first data, wherein the network connection between the external server and the load balancing device is disconnected after a data transmission is completed; selecting, by the load-balancing device, a server in the cluster and sending the second data to the server; and routing, by a routing unit in the cluster, the second data according to the control information of the second data, including sending the second data to a receiving server in the cluster, wherein the second data is obtained from the selected server and the receiving server is selected according to the server location information in the control information of the second data. sending, by a requesting server in the cluster, a request for connection to an external server; receiving, from the external server, a response to the request for connection and, in response, establishing the connection between the requesting server in the cluster and the external server; sending a first data comprising a first controlling identity record from the requesting server in the cluster to the external server, wherein the first controlling identity record includes a unique identity and a control information, wherein the control information contains server location information identifying a desired server in the cluster; disconnecting, by the requesting server in the cluster, the connection between the requesting server in the cluster and the external server; receiving, by the load balancing device in the cluster, a request for a new network connection from the external server; upon establishing the network connection, receiving a second data at the load balancing device in the cluster from the external server, wherein the second data is obtained by processing the first data by the external server and contains a second controlling identity record including the unique identity and the control information received by the external server in the first data, wherein the network connection between the external server and the load balancing device is disconnected after a data transmission is completed; selecting, by the load-balancing device, a server in the cluster and sending the second data to the server; and routing, by a routing unit in the cluster, the second data according to the control information of the second data, including sending the second data to a receiving server in the cluster, wherein the second data is obtained from the selected server and the receiving server is selected according to the server location information in the control information of the second data.