Inclusion Criteria:  ≥ 18 and ≤ 75 years of age; Histological or cytological confirmed advanced metastatic colorectal cancer; Refractory to at least second line standard treatment containing fluorouracil, oxaliplatin and irinotecan; At least one measurable lesion (larger than 10 mm in diameter by spiral CT scan or 20mm by conventional CT scan); ECOG performance status of 0-1; Life expectancy ≥ 12 weeks; No previous treatment with vascular endothelial growth factor receptor (VEGFR) inhibitor (TKI); Signed and dated informed consent; Adequate hepatic, renal, heart, and hematologic functions; Willingness and ability to comply with scheduled visits, treatment plans, laboratory tests, and other study procedure.  Exclusion Criteria:  Pregnant or lactating women; Any factors that influence the usage of oral administration or any disease or condition that affects drug absorption; Previous treatment with TAS-102; Participated in clinical trials of other drugs within four weeks before enrollment; Received other systemic anti-tumor therapy within 4 weeks before enrollment, including chemotherapy, signal transduction inhibitors, hormone therapy and immunotherapy; International normalized ratio (INR) > 1.5 or partially activated prothrombin time (APTT) > 1.5 × ULN; Clinically significant electrolyte abnormalities; Subjected with hypertension that cannot be controlled by drugs, which is specified as: systolic blood pressure ≥ 140 mmHg and / or diastolic blood pressure ≥ 90 mmHg; Unrelieved toxic reactions higher than CTCAE V5.0 grade 1 caused by any previous anti-cancer treatment; Incomplete healing of skin wound, surgical site, traumatic site, severe mucosal ulcer or fracture; Conditions that may cause gastrointestinal bleeding and perforation determined by the researcher; History of arterial thrombosis or deep venous thrombosis within 6 months before enrollment; Stroke and / or transient cerebral ischemia occurred within 12 months before enrollment; Cardiovascular diseases with significant clinical significance; LVEF<50%; Congestive heart failure New York Heart Association (NYHA) grade > 2; Evidence of CNS metastasis; Previous treatment with VEGFR inhibition; Ventricular arrhythmias requiring drug treatment; Proteinuria ≥ 2+ (1.0g/24hr); Coagulation dysfunction, hemorrhagic tendency or receiving anticoagulant therapy; Other malignant tumors in the past 5 years, except skin basal cell or squamous cell carcinoma after radical surgery, or cervical carcinoma in situ; Active infection that is not controlled clinically, such as acute pneumonia, active hepatitis B or hepatitis C; By judgment of the investigator, there are concomitant diseases that seriously endanger the safety of the patient or affect the completion of the study.