Thickness measurement method based on overlapping peak signal decomposition

The invention provides a thickness measurement method based on overlapped peak signal decomposition, which comprises the following steps: collecting light intensity of a pre-focusing photoelectric detector and a post-focusing photoelectric detector and focusing lens displacement corresponding to the light intensity, and obtaining upper surface reflection light intensity signals and lower surface reflection light intensity signals of a to-be-measured object for decomposing light intensity signals through iterative updating of an algorithm; and obtaining zero crossing point position information of the differential confocal signal curve according to the decomposed light intensity signal so as to obtain the thickness of the object to be measured. According to the thickness measurement method provided by the invention, accurate measurement of the micron-sized thickness thin film is realized only through an algorithm without any additional optical element, and the measurement range and the application occasion of a