Objective To investigate the diagnosis value of low-dose spiral CT scanning technology in adullt pulmonary tuberculosis. Methods Choose 150 cases of tuberculosis patients, and divide them into two groups using the completely randomized method. Then adopt conventional-dose and low-dose scanning methods in these patients. Philips 64-slice spiral CT is adopted and electric current of conventional-dose scanning tube is 230mA. According to different BMI, different electric current is available: BMI≤18.5, 20mA, 18.5<bmi<24.9, 30ma.="" 40ma.="" compare="" the="" differences="" between="" cross="" coronal="" planes="" and="" quality="" of="" focuses="" infection="" in="" these="" two="" methods.="" results="" image="" sections="" lung="" window="" mediastinal="" scanning="" methods="" are="" consistent.="" window:="" p="" plane="" groups="" is="" not="" statistics="">0.05). Depented on the comparison of tuberculosis CT images, the P value of eight characteristics are bigger than 0.05. Make two samples of the Radiation dose between the two groups of subjects and take the average test. The result is the P value is more smaller than 0.01. Compared with the average noise level between the two groups, P value is smaller than 0.01. Conclusion There is no significant difference between conventional-dose and low-dose scanning technology in the aspect of adult tuberculosis diagnosis and the detection effect of common imaging sign. As a result, lowdose scanning technology reduces the radiation dose of subjects significantly.