A new type of photonic crystal all-optical switching based on the dynamical shift of defect mode has been designed. This photonic crystal is triangular lattice with circular air holes in silicon, in which line defects and point defects are included. A photonic crystal structure introducing both point and line defects which has quality defect mode is designed. After that, point defects have been filled with the Kerr nonlinear optical materialpolydiacetylene para-toluene sulfonate (PDA-PTS). With regulating the control light, the defect mode brings the dynamical shift, and accordingly it can be controled the signal light on and off. The two-dimensional finite-difference time-domain (FDTD) calculation has been used to numerical demonstration. The results show that the switch has great extinction ratio, low threshold power density, and fast switching time. The photonic crystal all-optical switching based on the dynamical shift of defect mode has an important academic significance to the high-speed all-optical communications, as well as the optical computing technology in the future.