Current scientific findings suggest that lung cancer patients need to undergo genetic testing before using targeted drug therapy. Targeted drug therapy is to target the specific molecules of tumor tissues or cells’ driving gene variations and tumor-related signaling pathways, and use molecular targeted drugs to specifically block the biological function of the target and selectively reverse the malignant biological behaviors of the tumor cells, so as to achieve the purpose of tumor growth inhibition. Without genetic testing, it is impossible to select appropriate target drugs, and inappropriate target drugs cannot play the role of inhibiting tumor growth, thus failing to achieve the role of treating lung adenocarcinoma. Therefore, targeted drugs can only be used when there is corresponding gene mutation, and blind use of targeted drugs cannot get good clinical efficacy. Therefore, before using targeted drug therapy, lung cancer patients should go to regular medical institutions, complete the examination, and choose appropriate drug therapy under the guidance of doctors.