A failure analysis method and device, where the method includes obtaining a frequency domain response amplitude of a channel from a hybrid fiber-coaxial (HFC) network, performing linear fitting on an effective portion of the frequency domain response amplitude to determine a channel slope value, and performing channel failure analysis according to the channel slope value. Failure analysis is performed according to the obtained channel slope value, and the channel slope value is a new failure analysis parameter. In this way, means of channel failure analysis increase, and channel failure analysis is more accurate.