X-ray diffraction experiments were conducted on Zr base, Fe base, Ge base amorphous metal and several other kinds of amorphous material. On the other hand, computer simulations of X-ray diffraction of these materials were also developed, by means of applying Debye formula and Ehrenfest’s Formula, on the Ideal Amorphous Model (IAS). The results of the experiments and simulations were compared and analysed; however, although some results had high agreement between experiment and simulation, a portion of materials gave inconsistent results. The reasons of the inconsistency were found and analysed; a further developed X-ray diffraction simulation method was developed by using Generalized Debye Formula; and instead of IAS model, a new and more specific model were obtained, by using new simulation atomic packing technique. Finally, more accurate models were found and Generalized Debye Formula is introduced, which successfully solved the problem of disagreement of experiment and simulation X-ray diffraction results.