Provided are a method and device for providing a video of an Internet Protocol TV or Interactive Personal TV (IPTV) service. The method includes: detecting whether an IPTV service system is accessible for a Set Top Box (STB) or not; and when the IPTV system is detected to be inaccessible for the STB, providing a video for the STB through a Content Delivery Network (CDN) subsystem. By the technical solution, the technical problems that the user cannot enjoy services such as the video service in case of upgrading, server failure or network failure in the related technology are solved, and live video service can still be provided for the user even though the service of the IPTV service system is inaccessible due to upgrading, server failure or network failure.