The paper applied the BP nerve network processing many the spectral measurement data,and made use of the MATLAB nerve network tool box to carry on calculator′s imitate true experiment,and analyzed the influence of random voice to measurement result.Experimental result proved that the method could cancel the assumption model of emissivity and wave-lengths,overcoming limit of minimum two multiplications which resolve the above-mentioned problem.It is a kind of valid method to acquire the true temperature and spectral emissivity.