The invention provides an art terminal detection method adopting broadband reflecting measuring method, which is used for confirming the vertical size of the structure in part of the pattern substratein the manufacturing process of pattern substrate. The method comprises steps as follows: obtaining a measuring net reflection spectrum which is generated by irradiating at least part of the patternsubstrate by the beam with broadband spectrum; calculating the net reflection spectrum of weighting incoherent modeling of reflectivity in different areas which form part of the pattern substrate; forthe wavelength which is less than the selective conversion wavelength in the broadband spectrum, calculating the reflectivity of every area by adopting the first optical model, and the reflectivity is regarded as the weighting coherence of reflecting field of film lamination which is corresponding to the transverse different area forming the area; confirming a group of parameters matching closelybetween the measuring net reflection spectrum and the modeling net reflection spectrum; and extracting vertical size of the structure in part of the pattern substrate from a group of parameters.