Because it is consistent with many astronomical phenomena and successfully predicted the cosmic microwave background radiation (CMBR) and cosmic abundance, the theory of universe expansion has been widely recognized by the scientific community. Hubble's law is the foundation of universe expansion theory, but 100 years of observations have shown that Hubble parameters are not constants, and with the improvement of Hubble parameter measurement accuracy, the problem of inconsistent Hubble parameters obtained by different star types and different methods has become more and more difficult to solve. So the cosmological redshift may not only be related to distance but also to other factors, and the universe may not be really expanding. The Compton effect of free electrons and low energy photons has been observed in the laboratory. Photons interact with a large number of free electrons on their way to us from a distant source (free electron Compton scattering FEC). FEC causes photons (plane electromagnetic waves) to redshift, and the photon beam to expand along the propagation direction, these produce the illusion of cosmic expansion, showing the same astronomical phenomena as the expansion of the universe (FEC model).