Bone metastasis of lung cancer is not easy to be detected in blood routine, and only some patients with bone marrow metastasis may have abnormal changes in blood routine, such as decrease in white blood cells, hemoglobin, platelets and other indexes. Bone metastasis of lung cancer usually occurs through blood circulation, and bone metastasis is easy to cause bone destruction, and clinically patients often have symptoms such as localized bone pain, limb activity disorder, soft tissue lumps and so on. If lung cancer metastasis occurs in bone but not in bone marrow, patients’ blood routine is usually normal. Only when bone metastasis of lung cancer invades bone marrow and the bone marrow damage causes abnormal hematopoietic function of human body, lung cancer patients may have blood routine results of reduced white blood cells, platelets, hemoglobin and other three series.