The invention discloses a boiler superheater slagging diagnosis method and a boiler superheater slagging diagnosis system on the basis of vibration signal characteristic analysis. According to the method, a vibration signal of an external furnace connecting tube of a tube panel of a superheater of a power station boiler is acquired in real time by a vibration acceleration sensor, a digital vibration signal is generated by a data acquisition device, extraction and calculation are carried out by utilizing a central processing unit to obtain characteristic parameters of the digital vibration signal, the characteristic parameters are combined vibration signal characteristic parameters which are under the same working conditions and in a state that a heated surface of the boiler superheater is clean to carry out calculation and analysis, and by comparing obtained an obtained value with a slagging threshold value, a slagging state of the superheater is diagnosed, so that monitoring and diagnosis on a slagging fault of the superheater in the operating process of the power station boiler are implemented and safety of operation of the boiler is ensured.