The three-dimensional elastoplastic thermo-mechanical coupled finite element model of laser forming for pure aluminum plates is established with nonlinear finite element analysis software Msc.Marc. Circular, square, rectangular 1/4 ( the size ratio of laser spot along the laser scanning direction and its vertical direction is 1:4, same as below) and rectangular 4/1 laser spots with the same area are chosed as the heat sources. The bending properties of sheet metal with four different laser source modes are simulated, and the temperature field, displacement field, stress and strain field are analyzed. The results show that the circular laser spot acquires the highest temperature peak value and temperature differences between upper and lower surfaces, while the rectangular1/4 laser spot acquires the largest width of high temperature zone. The rectangular 1/4 laser spot which owns the widest plastic strain zone and highest total plastic strain differences between upper and lower surfaces obtains the highest bending angle,and also the lowest residual stress.