• The patients signed the informed consent and voluntarily joined the study;

• Age 18-75 years old, male or female;

• Patients with advanced breast cancer diagnosed by histopathology or cytology, who are receiving and continue to receive the same chemotherapy regimen;

• Can accept the current chemotherapy regimen (must be platinum-containing chemotherapy regimen: lobaplatin, carboplatin, cisplatin, etc.) for at least 2 cycles;

• The first occurrence of platelets \<50×109/L in the current chemotherapy cycle;

• The investigator determines that the patient can receive hetrombopag administration;

• Neutrophil count ≥ 1.0×109/L, hemoglobin ≥ 80g/L before administration of Haitrombopag;

• Life expectancy at screening ≥ 12 weeks;

• ECOG: 0-1;

⁃ The main organ functions are normal, and there are no serious complications.