The invention provides a method for distinguishing geometrical characteristic changes generated before and after integral panel part engineering is changed. The method is characterized in that when the geometrical characteristic changes generated before and after integral panel part engineering is changed are distinguished, firstly, models generated before and after design is changed are placed at the same coordinate position in space, the appearance face of the model generated after the change is dispersed, thickness values, at all dispersion points, of the models generated before and after the change are calculated independently, the thickness-direction size deflection value, at the same dispersion points, of the models generated before and after the change is judged, the dispersion points with the deflection exceeding the distinguishing accuracy are marked, and changed characteristics can be judged through the positions where the dispersion points with the deflection exceeding the distinguishing accuracy are located. By means of the method, the current situation that changed parts are distinguished only by manually observing the models can be effectively changed, the part production cycle can be shortened, and the manufacturing accuracy can be improved.