The application of pulsed laser welding technology increases in precision manufacturing. The study on the deformation characteristic of pulsed laser welding has a special significance for improving the quality of welding. A three-dimensional finite element method model is established by the shell element in ANSYS. The model simulates the process of pulsed laser welding of Hastelloy C-276 with 0.5 mm thickness. Experiments are carried out to measure the welding distortion, and the simulation results have a good agreement with the experiment results. Then, the model is used to further study the effect of single-pulse laser energy input on the transverse shrinkage distortion and buckling distortion. The results show that the periodic oscillation of the immediate distortion is caused by the pulsed laser wave. With the single-pulse laser energy input increasing, the transverse shrinkage and buckling distortion are improved.