Thrombocytosis genes are completely negative may be due to secondary thrombocytosis, and the possibility of chronic myeloproliferative disorders cannot be excluded. Thrombocytosis can be categorized as secondary thrombocytosis and primary thrombocytosis according to its etiology. Post-splenectomy, bacterial infection, recovery from cerebral hemorrhage and other diseases may lead to a secondary increase in platelet count, which can be recovered on its own after the primary cause is cured, and the results of the MPN gene test in these patients are all negative. Thrombocytosis caused by primary thrombocythemia, leukemia and other chronic myeloproliferative diseases is primary thrombocythemia, and most of the patients have positive MPN gene test results, but a small number of patients have negative MPN gene test results. It is recommended that the patient should consult the hematology department in time, complete the examination such as bone marrow aspiration and biopsy to further clarify the cause of thrombocytosis, and treat the cause of the disease.