Effect of fabrication error on the absolute bandgap of two-dimensional 12-fold photonic quasicrystals (PQCs) is numerically investigated by using the finite difference time domain (FDTD) method. Results indicate that, i) the effect of the size error is bigger than that of the position error; ii) the absolute bandgap is more sensitive to the bandgap of TE mode than its TM mode; iii)the bigger the fabrication error, the narrower the absolute bandgap of 12-fold PQCs is. In the current fabrication conditions, the effect of the fabrication error can be almost ignored for the 12-fold PQCs which lattice constant is bigger than 500 nm. However, if lattice constant of 12 PQCs is less than 200 nm, its absolute bandgap even disappear completely and cannot be used as absolute bandgap materials.