We present an alternative theoretical model andinterpretation of the cosmological redshift based on quantumoptical theory. Our model shows that the energy dissipation of photon due to the interaction of photon with the cosmic matter, electromagnetic vacuum and gravitational field is the main cause of the redshift. Based on the new perspective, the general formula of the cosmological redshift is derived and it is shown that the Hubble law is a special case of this formula. Moreover, the speeding up of the expansion of the universe that the standard cosmological model describes is newly interpreted as a natural result that the newmodel of the redshift provides. Our interpretation of Hubble’s law based on quantum optics is distinguished from the conventional theory in that the theory does not require assumptions such as mysterious dark matter and dark energy that, despite long-term efforts, have not passed experimental test in laboratories at all. Furthermore, our interpretation is free of paradoxical problems associated with dynamic description of the expansion of the universe. Conclusively, it isdemonstrated satisfactorily that the Hubble law is irrelevant to a whole evolution of the universe and instead is due to the energy dissipation of photon interacting with the cosmic matter, electromagnetic vacuum and gravitational field.