The invention discloses a dustproof component, a soil gas detection sampler and an application method of the sampler and belongs to the field of gas detection equipment. The dustproof component comprises an inner-layer mesh enclosure and an outer-layer mesh enclosure, wherein the side wall of the inner-layer mesh enclosure is provided with inner-layer filtering holes which are arranged uniformly in the circumferential direction; and the outer-layer mesh enclosure is rotationally arranged at the periphery of the inner-layer mesh enclosure in a sleeving mode, and the side wall of the outer-layermesh enclosure is provided with outer-layer filtering holes in one-to-one correspondence with the inner-layer filtering holes. The soil gas detection sampler is formed by assembling the dustproof component. In the using process of the sampler, gas inlets are prevented from being blocked in the process that the sampler is inserted into and pulled out of a detection hole; and the possibility of blockage of the gas inlets can be lowered in the gas extracting process, the extracted gas is purer, and detection accuracy is improved.