• Signed written informed consent before any study-related procedure.

• Age ≥ 18 years.

• ECOG PS of 0 to 1 at screening,and with no clinically significant deterioration in the previous 2 weeks.

• Expected survival ≥12 weeks.

• Histologically or cytologically confirmed metastatic Non-Small Cell Lung Cancer (International Association for the Study of Lung Cancer and Joint Committee on the American Classification of Cancer, TNM Lung cancer stage 8). Documented validated results from local testing of either tumor tissue or blood confirming the presence of EGFR 19del or exon 21del L858R mutation. These mutations above may exist alone or together.

• According to RECIST 1.1, patients must have at least one central nervous system (CNS) metastatic tumor lesion at baseline that meets the following requirements: accurately and repeatably measurable at baseline, have no radiotherapy or biopsy.

• Patients who have untreated for advanced/metastatic non-small cell lung cancer, including chemotherapy, biological therapy, targeted therapy, immunotherapy, or experimental therapy, prior to initiation of study drug therapy. Patients who have received adjuvant therapy or neoadjuvant therapy (chemotherapy and/or radiotherapy) are allowed to enroll if there is no progression within 6 months of treatment. Patients who have received topical therapy (radiotherapy or perfusion therapy) are allowed to enroll if the lesion within the local therapeutic area is non-targeted.

• For premenopausal women with childbearing potential, a pregnancy test must be performed within 14 days before the first dose, and the pregnancy test (blood or urine test) must be negative; female subjects must not be lactating;

• Willing to use contraception.

• Voluntary and agree to follow the study treatment protocol as well as follow-up plan, and can accept the oral medicine treatment.