The invention relates to an implementation method of a pilot-assisted detector for DVB-T signals in a cognitive radio network. Most countries in the world use DVB-T as the signal standard for ground digital televisions, the nodes in a cognitive radio network acquire spectra-available information on the wave band of the digital television signals mainly by means of spectra perception, and therefore, the research into spectra perception methods for DVB-T signals has significant value. The invention provides a pilot-assisted detector for DVB-T signals. Firstly, a processing unit in the detector strengthens the periodic pilot components in a DVB-T signal received by a secondary user through the sum of product movements but inhibits other components; and secondly, a combination and judgment unit in the detector combines the outputs of the processing unit and judges whether a master user signal exists. The theoretical analysis and the simulation result indicate that the detector is free from the effects of multidiameter Rayleigh fading, can differentiate the master user signal from interference under the conditions of no synchronizing information and low signal-to-noise ratio, and enhances the detection performance.