Investigating codimension two bifurcations in neutral differential-difference equations may reveal thecomplicated dynamics． In this paper，center manifold reduction method is established to derive the normal formsnear the codimension two bifurcations in NDDE． We first introduce the decomposition of the phase space of NDDE．Then the normal form method to reduce a NDDE onto an invariant center manifold is obtained． Finally，BT bifurca-tion in van de Pol＇s equation with extended delay feedback is considered and the detailed dynamics，including theglobally existed homoclinic orbits，are obtained near the equilibrium．