The invention relates to an EXCEL-based indirect type analog quantity original data acquisition method, comprising an image acquisition process and a data restoration process, wherein photographing equipment is used for shooting a curve on a display of the original control system in an industrial field in the image acquisition process, so as to acquire an analog quantity curve image acquired by adata acquisition system integrated in the original control system; and in the data restoration process, the acquired analog quantity curve image is imported into EXCEL, by establishing and drawing a curve, restoring all the real data point information of the curve, and saving the data point information as a file in a certain data format. The method provided by the invention adopts non-contact acquisition, can complete data acquisition without being accessed to the control system, is high in security, has no influence on an industrial control system, is independent of a brand of a control system used in an industrial control field, does not need to consider compatibility of different communication protocols between systems and is strong in universality.