Objective to explore the lung nodules in qualitative diagnosis use glass grinding the diagnostic value of CT multiplanar reconstruction postprocessing techniques. Methods Selection method conforms to the standard of 86 cases of patients, all row multislice CT chest thin layer after the reconstruction, patients were retrospectively analyzed clinical data, to the differential diagnosis of pulmonary grinding of glass image, with the pathological results as a diagnostic criteria, it can be divided into malignant and benign group, at the same time to choose more planar CT scanning layer thickness 5 mm for the control group, observe and analyze the imaging features. Results two groups of patients with pleural sag), burr, Ye Zheng, cavitation character and boundary clear signs, compared the results with statistical difference (P<0.05); Two groups of patients in irregular shape, round or oval, patchy and multiple nodules fusion shape comparison, the results statistically difference (P<0.05); 5 mm thick regular spiral CT scan and spiral CT multiplanar reconstruction of 1 mm layer control, of GGO malignant signs show statistically significant (P<0.05). Research shows that: the more benign lesion group characterized by round or oval, malignant lesion group is more irregular and multiple nodules fusion is given priority to. Conclusion Spiral CT multiplanar reconstruction of pulmonary grinding glass nodules qualitative diagnosis of great value in clinical application.