Based on the non-paraxial diffraction theory and experimental results of the far-field distributions of diode lasers and by means of the amplitude-phase retrieval algorithm，a novel method for simulating source-field distribution of the diode laser is proposed. The simulation procedure is described and illustrated by the example of a double-heterostructure diode. It is shown that this method is precise enough so long as acurate experimental data are available，and would find some practical applications.