It is reported that the Large High Altitude Air Shower Observatory (LHAASO)
observed very high energy photons from GRB 20221009A, with the highest energy
reaching 18 TeV. We find that observation of such high energy photons is a
quite nontrivial fact since extragalactic background light could absorb these
photons severely and the flux is too weak to be observed. Therefore we discuss
the potential new mechanism for us to observe these photons, and suggest that
Lorentz invariance violation induced threshold anomaly of the process
(\gamma\gamma\to e^-e^+) provides a candidate to explain this phenomenon.