The embodiment of the invention provides a method and a device for thin stratum identification based on high-density VSP (Vertical Seismic Profiling) data. The method comprises the steps of: obtainingVSP data with an assigned collection density of a target area, and performing preprocessing of the VSP data; obtaining a VSP frequency spectrum curve and a first arrival amplitude derivative curve ofthe VSP data after preprocessing; multiplying the VSP frequency spectrum curve by the first arrival amplitude derivative curve, and obtaining a combined curve; and obtaining a stratum identificationresult of the target area according to the combined curve. According to the embodiment of the invention, the resolution of thin stratum identification can be improved.