Double Decent elliptical Gaussian beams solution to the wave equation were obtained. By the generalized Collins integral,the propagation characteristics of Double Decent elliptical Gaussian beam passing through an ABCD was studied;the propagation formula of passing through optical systems was derived;the analytical expressions of intensity distribution is derived and numerical examples is illustrated. It was furnished in analyzing physically the propagation properties of the beams of high-power laser diodes. This novel model was used for describing the beam output characteristics of high-power laser diodes. The theory result matches experiment result well.