The invention discloses a separation device, which comprises a sample collector, a filter, a connector, a capturer and a filtrate collector, the sample collector and the filtrate collector are both containers, the filter comprises a filter screen, the capturer comprises a capture chip with the aperture of 0.01-1000 [mu] m, the connector is a barrel-shaped object, and the sample collector, the filter, the connector, the capturer and the filtrate collector are connected in sequence. According to the separating device disclosed by the invention, before samples such as clinical hydrothorax and ascites, urine and the like are transferred to a laboratory for detection, particulate matters to be detected in the samples can be separated and fixed at the same time at a sampling site, the intact forms of cells are kept, the cells are prevented from disintegration and degradation of biomacromolecules in the cells are prevented, and microbial pollution and reproduction are avoided; the false negative rate caused by the storage and transportation process of the sample is effectively reduced, and the detection rate of tumor cells is greatly improved.