The invention discloses an application of miR-3923 in judgment whether lung squamous carcinoma metastasis is caused or prejudgement of lung squamous carcinoma metastasis risk. Accordingly, miR-3923 can be used for developing a medicine used for inhibiting lung squamous carcinoma metastasis and invasion or preventing the lung squamous carcinoma metastasis and invasion. Research results of the invention provide fundamental basis for making an individual treatment plan by a clinician and also can provide a new medicine target for development of a lung squamous carcinoma metastasis invasion medicine.