Slagging on the exchanger surfaces in boiler in power plants is still a serious issue that reduces thermodynamic efficiency and threatens the operation of the generation unit. In this paper, an innovative slagging diagnosis method based on the analysis of vibration signal of the exchanger tube panels is proposed to monitor the slagging condition. We build a scaled-down tube panel according to the actual structure of the superheater panel in laboratory to study the relationship between vibration signal and varied slagging conditions and air speed. Root Mean Square (RMS) in time domain and wavelet packet decomposition in frequency domain are employed to extract the features from vibration signals and predict the slagging condition without shut-down in the future. It is found that RMS value of the tube panel signals decreases with the increase of slagging weight, especially at a low air speed. Relative signal energy in a certain frequency band will experience significant change after tube panel slagged. In order to verify the experimental result on the feature changes of the tube panel vibration signals with varied slagging conditions, we successfully demonstrate our laboratory result via analysis of vibration signals of a superheater tube panel in Banshan Power Generation (Hangzhou). It indicates that the vibration signals of tube segment between the header and furnace wall of the superheater panel can be collected and used for slagging diagnosis in a running pulverized coal boiler. Our study is promising for prediction of slagging and furtherly reduce the risk induced by slagging of exchanger panel in the boiler.