A method for guaranteeing website resource utilization rate using a content delivery network, comprising following steps: receiving a domain name resolution request sent by a local domain name server (102, 602); monitoring a resource load of a website source site (101, 601) corresponding to the domain name resolution request; utilizing monitoring data and according to a predetermined strategy, determining whether a result of the domain name resolution request is an address of the website source site (101, 601) or a content delivery network system (105, 605); and sending a domain name resolution result to the local domain name server, wherein the step of utilizing the monitoring data and according to the predetermined strategy to determine the result of the domain name resolution request is the address of the website source site (101, 601) or the content delivery network system (105, 605) further includes: selecting a scheduling strategy, wherein parameters of the scheduling strategy include a preset upper limit and a preset lower limit of the resource load, and the address of the website source site; and making a decision according to the resource load and a selected scheduling strategy, comprising: resolving the domain name resolution request into the address of the website source site at an initial moment; when the resource load of the website source site is within the preset upper limit and the preset lower limit, remaining a resolution ratio to be unchanged; when the resource load of the website source site exceeds the preset upper limit, increasing the resolution ratio to gradually guide the traffic to the content delivery network system; and when the resource load of the website source site is lower than the preset lower limit, reducing the resolution ratio to gradually guide the traffic back to the website source site, wherein the resolution ratio is a ratio of the domain name resolution request being resolved into the content delivery network system. receiving a domain name resolution request sent by a local domain name server (102, 602); monitoring a resource load of a website source site (101, 601) corresponding to the domain name resolution request; utilizing monitoring data and according to a predetermined strategy, determining whether a result of the domain name resolution request is an address of the website source site (101, 601) or a content delivery network system (105, 605); and sending a domain name resolution result to the local domain name server, wherein the step of utilizing the monitoring data and according to the predetermined strategy to determine the result of the domain name resolution request is the address of the website source site (101, 601) or the content delivery network system (105, 605) further includes: selecting a scheduling strategy, wherein parameters of the scheduling strategy include a preset upper limit and a preset lower limit of the resource load, and the address of the website source site; and making a decision according to the resource load and a selected scheduling strategy, comprising: resolving the domain name resolution request into the address of the website source site at an initial moment; when the resource load of the website source site is within the preset upper limit and the preset lower limit, remaining a resolution ratio to be unchanged; when the resource load of the website source site exceeds the preset upper limit, increasing the resolution ratio to gradually guide the traffic to the content delivery network system; and when the resource load of the website source site is lower than the preset lower limit, reducing the resolution ratio to gradually guide the traffic back to the website source site, wherein the resolution ratio is a ratio of the domain name resolution request being resolved into the content delivery network system. selecting a scheduling strategy, wherein parameters of the scheduling strategy include a preset upper limit and a preset lower limit of the resource load, and the address of the website source site; and making a decision according to the resource load and a selected scheduling strategy, comprising: resolving the domain name resolution request into the address of the website source site at an initial moment; when the resource load of the website source site is within the preset upper limit and the preset lower limit, remaining a resolution ratio to be unchanged; when the resource load of the website source site exceeds the preset upper limit, increasing the resolution ratio to gradually guide the traffic to the content delivery network system; and when the resource load of the website source site is lower than the preset lower limit, reducing the resolution ratio to gradually guide the traffic back to the website source site, wherein the resolution ratio is a ratio of the domain name resolution request being resolved into the content delivery network system. resolving the domain name resolution request into the address of the website source site at an initial moment; when the resource load of the website source site is within the preset upper limit and the preset lower limit, remaining a resolution ratio to be unchanged; when the resource load of the website source site exceeds the preset upper limit, increasing the resolution ratio to gradually guide the traffic to the content delivery network system; and when the resource load of the website source site is lower than the preset lower limit, reducing the resolution ratio to gradually guide the traffic back to the website source site, wherein the resolution ratio is a ratio of the domain name resolution request being resolved into the content delivery network system.