Power quality has always attracted attention. The number of power electronic equipments in the power system and harmonics generated are increasing. The problem of harmonics has always been a topic of concern. This paper proposes a frequency estimation algorithm for power system harmonics and inter-harmonics by introducing the compressed sensing theory and the parallel factor model. First， this paper obtains the data at the signal receiving end， uses Euler’s formula to convert the sine signal into a spatial signal， and constructs the multi-delay output into a parallel factor model. Second， we compress the three slices of the model， and use the trilinear alternating least squares algorithm parallel factorization（PARAFAC）. Finally， the obtained data is sparsely reconstructed to obtain the frequency of the automatic pairing. Compared with the traditional parallel factor algorithm， this method has a compression process， a minor calculation， and lower storage capacity requirements. The frequency estimation performance of the proposed algorithm is very similar to that of the traditional PARAFAC method and better than that of the estimating signal parameter via rotational invariance techniques （ESPRIT） method.