A simultaneously measuring method for Zn(II)、Co(II) based on feature interval association-partial least squares is proposed to solve the problem that the ultraviolet visible (UV-Vis) absorption spectrum of mixed solution with Zn(II), Co(II) is seriously overlapped and difficult to separate. For the absorption spectrum in the range of 400~800 nm of mixed solution, the method of feature interval association is used to select the characteristic interval of Zn(II) and Co(II) in the way of partition, and the optimal feature interval of Zn(II) and Co(II) is selected by the minimum root mean square error of cross validation VRMSECV and the maximum determination coefficient R2. Finally, these optimal intervals are associated to establish partial least squares (PLS) model, and ion concentrations of Zn(II) and Co(II) are obtained. The result indicates that the proposed method can not only reduce the complexity of the wavelength selection, but also ensure the stability of the wavelength selection process. Thus, the VRMSECV and the predicted average relative error of Zn(II) model are reduced to 0.0483 and 3.48%. The VRMSECV and the predicted average relative error of Co(II) model are reduced to 0.0501 and 4.25%. And the R2 of Zn(II) and Co(II) are increased to 99.41% and 99.22%. In addition, the application of the method can fix the scanning spectrum of Zn(II) and Co(II) in the selected feature intervals, which greatly improves the efficiency of spectrum detection.