Abstract: According to the concept of fractal dimension,the author puts forward a method of fuzzy control filter based on short-time fractal dimension.That method brings up new algorithm of network fractal dimensions and short time fractal dimensions,and fuzzy control parameter is discussed.In virtual instrument( VI) Lab VIEW 6.i software workbench,real-time detection of the current conduction interference signal in digital PCB is realized.By signal processing,the system has the following measurement functions：signal-noise spearation，power spectrum of current conduction interference signal,etc.Result shows that the method is feasible and effective.

Key words: digital PCB, current conduction interference, real-time detection, short time fractal, fuzzy control