Using RS2000SM CO2 laser of 2.5 kW to irradiate the nodular cast iron (QT-450) plate, and altering the process parameters during laser forming, and analyzing test samples with the X-ray stress analysis instrument (type: X-350A), digital microhardness tester HVS-1000 and scanning electric microscope (SEM) respectively, laser forming regularity of brittle material is studied. The results show that increasing the laser power and the feed number of the beam, decreasing the scanning speed, and the thickness of the test sample eventually result in the increase of the bending angle. There are ferrite and cementite in the surface layer of the test sample after laser forming. The number of ball graphite in the surface layer decreases; The maximum tensile stress of the upper surface in test sample is about 250 MPa, the residual stress value of the lower surface in test sample is about zero. The hardness of the test sample in cross section varies between 700HV and 200HV, the hardness near the upper surface is the greatest. The microcrack inside the deforming area appears when the energy of laser beam is quite strong.