The invention relates to a platform device for collecting trace materials in a water sample, and an application of the platform device. The platform device comprises a sampling system, a filtering system, a chromatographic system and an elution system; a sampling outlet of the sampling system is connected with a two-stage filter of the filtering system through a water pump, a water sample enters a steady flow tank after filtration, a valve is arranged between the steady flow tank and an eluting solvent storage tank, and connected with a constant flow pump, and the constant flow pump is connected with a chromatographic column and a receiving container through the elution system; and the water pump drives a sample feed port to sample the water sample, the suspended matter in the water sample is filtered through the filtering system, enters the steady flow tank for temporary storage, and then is pressed into the chromatographic column/ball via the constant flow pump, the trace materials in the water sample are specifically absorbed, the switching of the valve is controlled before the trace materials reach the leakage volume of the chromatographic column, the absorbed components are eluted through the elution system with a strong polar solvent and collected, and the enrichment of the trace materials in the water sample is realized. The platform device is simple in process flow, convenient to operate and high in adaptability.