The present invention relates to use of two microRNAs in detection of lung cancer prognosis and in medicine preparation. Particularly, the invention relates to a composition comprising two small RNA molecules microRNA-150 and microRNA-886-3p, a device comprising the composition used in detection of lung cancer prognosis and in preparation of medicaments for inhibiting mammal and human lung cancer metastasis. Specifically, the expression levels of microRNA-150 and microRNA-886-3p can be used as the prognostic criteria of lung cancer prognosis, wherein high expression level of the gene combination indicates favorable therapeutic effect. The invention also relates to a device detecting the expression levels of microRNA-150 and microRNA-886-3p in mammalian and human lung cancer and a method for detecting the expression levels of microRNA-150 and microRNA-886-3p in samples.