Objective To investigate the effectiveness of dual-source dual-energy CT pulmonary angiography of the early diagnosis of patients with pulmonary embolism. Methods 40 patients with suspicious pulmonary disease were chosen in our hospital to receive treatment. All patients are dual-source dual-energy CT scan lung machine, with dual-energy scan data evaluation software were analyzed and the lungs into upper, middle and lower, the energy imaging were analyzed. MPR, MIP, VR, CTVE technology to reconstruct the original data were used. Results In 40 patients, 18 patients were diagnosed with pulmonary embolism, pneumonia in 4 patients, 3 patients with lung cancer, 15 patients with normal. 18 cases of patients with pulmonary embolism, a total of 218 emboli, which of central emboli 90, eccentric 46, mural-type 42, type 40 totally were occluded. 15 normal patients, their lung tissue perfusion were analyzed, the upper lungs and lungs, middle and lower comparative analysis, the difference was not statistically significant (t = 1.149,1.021,1.027,1.135, P> 0.05). The normal lung tissue perfusion and pulmonary embolism were analyzed, the upper lungs and lungs, middle and lower comparative analysis, the difference was not statistically significant (t = 6.394,6.092,6.607,6.862, P <0.05). Conclusion Dual-source dual-energy CT pulmonary angiography for the diagnosis of pulmonary embolism in patients has a very important sense and the ability to detect the disease at an early stage of pulmonary embolism, so it is worthy of promotion.