This invention discloses an in-situ monitoring method on the layer uniformity of sputter coatings in a vacuum chamber based on deconvolution of measuring plasma emission spectra. The method of the present invention started from an Ar-normalized Sr intensity distribution derived from deconvoluting the plasma spectra by using Abel inversion method, which was considered as the spatial distribution of the sputtering mass of the source target. The thickness profile on the substrate was then calculated with n-th power of cosine law model. It was observed good agreement between the calculated thickness profile based on spectroscopic measurement and experimental observation. The film uniformity for the same sputter conditions can be monitored by comparing in-situ measurement of Ar-normalized Sr intensity distribution with the standard curve, or by directly calculating thickness distribution on the substrates.