A hypertext transfer protocol, HTTP, scheduling system for a content delivery network, CDN, comprising: a central decision-making server, configured to generate central decision-making files based on bandwidths, load information, network condition, and cost information of edge server clusters; one or more central scheduling servers, connected to the central decision-making server, the central scheduling servers being configured to execute the central decision-making files, such that when receiving a client content request, based on a geographic location and a content of the client content request, the central scheduling servers select a preferred server cluster and determine whether a backup server cluster needs to be selected simultaneously, further return a re-directing address with an address of the preferred server cluster to the client, and simultaneously return a re-directing address to the client with an address of the backup server cluster when a backup server cluster is selected; and one or more edge scheduling servers, configured to be in a corresponding edge server cluster, characterized in that, when receiving the client content request, each edge scheduling server is configured to obtain a bandwidth and load information of the corresponding edge server cluster, determine if an address of the backup server cluster is included in the client content request received at the edge scheduling server, determine if the client content request needs to be directed to the backup server cluster, and direct the client content request to the backup server cluster when determining that the client content request needs to be directed. a central decision-making server, configured to generate central decision-making files based on bandwidths, load information, network condition, and cost information of edge server clusters; one or more central scheduling servers, connected to the central decision-making server, the central scheduling servers being configured to execute the central decision-making files, such that when receiving a client content request, based on a geographic location and a content of the client content request, the central scheduling servers select a preferred server cluster and determine whether a backup server cluster needs to be selected simultaneously, further return a re-directing address with an address of the preferred server cluster to the client, and simultaneously return a re-directing address to the client with an address of the backup server cluster when a backup server cluster is selected; and one or more edge scheduling servers, configured to be in a corresponding edge server cluster, characterized in that, when receiving the client content request, each edge scheduling server is configured to obtain a bandwidth and load information of the corresponding edge server cluster, determine if an address of the backup server cluster is included in the client content request received at the edge scheduling server, determine if the client content request needs to be directed to the backup server cluster, and direct the client content request to the backup server cluster when determining that the client content request needs to be directed.