The invention discloses a tiny RNA probe which is used for stomach tissue and a detection method hereof; the sequence of the probe consists of an oligonucleotide coding segment and an extended arm segment which are chemically modified; the oligonucleotide coding segment comprises the following tiny RNAs of hsa-miR-186, hsa-miR-20b, hsa-miR-18a, hsa-miR-181d, hsa-miR-424, hsa-miR-18b, hsa-miR-17, hsa-miR-20a, hsa-miR-106a, hsa-miR-374a, hsa-miR-224, hsa-miR-181, hsa-miR-25, hsa-miR-99a, hsa-miR-148b, hsa-miR-421, hsa-miR-199a-3p, hsa-miR-214, hsa-miR-92a and hsa-miR-574-5p; crossbreeding detection of the tiny RNA of the stomach tissue is implemented and the high-expression tiny RNA when the stomach tissue is cancerized can be detected; in this way, the high-expression tiny RNA is taken as a diagnosis mark of the cancerization of the stomach tissue; the tiny RNAs can be further designed to be the target points which orient the stomach cancer drug; therefore, the invention provides beneficial basis for judging stomach cancer and orienting the treatment.