Invasive lung adenocarcinoma is a highly malignant tumor, and genetic testing can provide doctors with a reference basis for the use of targeted drugs and drug changes. The cancer itself is not sensitive to the treatment effect of radiotherapy, and genetic testing is given to clarify whether there is a gene mutation before targeted drugs can be applied. Since patients with invasive lung adenocarcinoma may have metastatic cancer cells, targeted drugs can be given to other patients except for some patients in stage I if there is a clear genetic mutation. If there is no obvious change or even enlargement of the tumor in the course of treatment, the targeted drug treatment should be stopped, and then the targeted drug should be replaced if necessary according to the result of genetic test. Therefore, it is not difficult to see the importance of genetic testing in guiding the treatment of invasive lung adenocarcinoma patients.