Objective To study the changes in platelets and coagulation function in a rabbit model of breast cancer lung metastasis. Methods Twelve female New Zealand white rabbits were randomly divided into two groups: normal group and model group. A VX2 breast cell suspension was injected into the third breast pad and injected intravenously through the ear marginal vein. The mental state, diet, body weight, and tumor size of the rabbits were observed over 42 days. Platelet- related parameters (PLT, MPV, PDW, and PCT) and coagulation-related indexes (PT, APTT, TT, FIB, and D-dimer) were detected at corresponding time points. The levels of CD63 and CD62P TXB₂ in serum, and GMP-140 in plasma, were detected by ELISA. The tumor tissue and lung tissue were fixed with 10% formaldehyde, embedded in paraffin, sectioned, and stained with hematoxylin-eosin. Morphological changes in the tumor and lung tissue were observed under an optical microscope. Results The rabbit model of breast cancer lung metastasis was successfully established by injecting a VX2 tissue suspension into the breast pad and a VX2 cell suspension intravenously. The lung metastasis rate was 100%. The blood of the model rabbits was in a hypercoagulable state. The levels of PLT, MPV, and PCT increased significantly from 14 to 42 days, the PT, APTT, and TT indexes were significantly shortened, and the contents of FIB and D-dimer were significantly increased from 10 to 30 days. The levels of CD63, CD62P and TXB₂ in serum, and GMP-140 in plasma, increased significantly. Tumor cells increased in number, appeared loosely arranged, and were infiltrated by inflammatory cells in the mammary gland of model rabbits. A tumor cell mass with hemorrhage and necrosis was observed in the lung tissue, which contained hemosiderin deposition. Conclusions The blood circulation in the rabbit model of breast cancer lung metastasis was abnormal, and this manifested as platelet activation and a hypercoagulable state in the blood.