The high-precision measurements of the Hubble parameter make the theory of cosmic expansion more and more confusing, which bolster the idea that new physics may be needed to explain the mismatch. The cosmological redshift may not only be related to distance but also to other factors. The expansion of the Universe may be just an illusion. The Compton effect of free electrons and low energy photons has been observed in the laboratory. This article proposes a theory: Free electron Compton scattering (FEC) produce the illusion of the Universe exponential expansion: FEC causes photons to redshift (FEC redshift), and the photon beam expands along the propagation direction, that is, the redshift factor is (1 + z); the beam length stretch factor (time dilation of the supernova curve) is (1 + z); the expansion factor of the beam volume is (1 + z)3, and FEC will not be blurred Distant galaxy. The reason for rejecting the “tired light” does not hold in FEC.