To study the clinical diagnostic value of SPECT/CT bone imaging combined with two serum examinations in patients with bone metastases from pulmonary cancer. The clinical data of 120 patients consistent with pulmonary cancer admitted to the First Affiliated Hospitalof Hebei North University from March 2019 to December 2019 were selected for retrospective analysis, and they were divided into the bone metastasis group (n = 58) and non-bone metastasis group (n = 62) according to comprehensive evaluation result of X-ray, CT, MRI and clinical follow-up. The CT values of patients were obtained by SPECT/CT bone imaging to compare serum levels of ALP (alkaline phosphatase belongs to phosphoric monoester hydrolases, as a specific phosphatase, mainly in body tissues and body fluid) and BAP (bone alkaline phosphatase is formed by different modification and processing of alkaline phosphatase, and is mainly released by osteoblasts) and CT values of patients in both groups, using receiver operating characteristic (ROC) curve to evaluate the diagnostic efficacy of single detection and combined detection. SPECT/CT bone imaging in patients with bone metastasis from pulmonary cancer showed abnormal radioactive accumulation in spine, pelvis and bilateral ribs. Serum ALP, BAP and CT values in bone metastasis group were overtly higher than the non-bone metastasis group (P < 0.001). Logistic regression analysis showed that serum ALP, BAP and CT value were independent risk factors for bone metastasis from pulmonary cancer. The AUC value and Youden index of combined diagnosis were higher than those of single diagnosis. SPECT/CT bone imaging combined with serum detection of ALP and BAP in patients with pulmonary cancer is helpful for early diagnosis of bone metastasis, which provides more basis for the formulation and selection of clinical treatment options.