To evaluate the efficacy and safety of pyrotinib combined with capecitabine in patients with metastatic her-2 positive colorectal cancer after standard treatment.

Inclusion Criteria:

1. Patients should be histologically diagnosed with metastatic CRC and after receiving at least two standard treatment regimens；
2. Patients with HER2 positive；
3. Metastatic colorectal cancer (stage Ⅳ, T1-4N0-2M1)；
4. Life expectancy is at least 6 months
5. ECOG score 0-1；
6. The functional level of the major organs must meet the following requirements (no blood transfusion within 2 weeks prior to screening, no use of leukocytes or platelets)：

Exclusion Criteria:

1. The histopathological type is mucinous adenocarcinoma or ovarian implant metastasis；
2. Patients who have previously been treated with anti-Her2-targeted drugs；
3. Patients with surgical opportunity or potential for surgical treatment；
4. Patients with a high risk of bleeding or perforation due to a tumor that has apparently invaded adjacent organs (including large vessels) of the colorectal lesion or who have developed fistulas；
5. Patients with any severe and/or uncontrolled disease;
6. Patients with any or present brain metastases；
7. Women who were pregnant or breast-feeding.