  By extending original Kaluza-Klein theory to 6-dimension, the basic quantum
field equations for 0-spin particle, 1-spin particle and 1/2 spin particle with
mass >0 are directly derived from 6-dimensional Einstein equations. It shows
that the current quantum field equations of basic particles become pure
geometry properties under 6-dimension time-space. The field equations of
electron and photon can be unified in one 6-dimensional extended Maxwell
equation. The equations containing interactions between electron and photon
will be derived from Einstein equation under 6-dimension time-space. It shows
that the interactions in QED can be considered as the effect of local geometry
curvature changing instead of exchange virtual photons.
