Objective To study the best imaging parameters of digital tomosynthesis in detection of uroliths and the smallest diameter of the imaging calculi. Methods By using digital tomosynthesis, a in vitro model of uroliths was projected based on 4 different groups of imaging parameters (0.5, 1.0, 2.0, 4.0 mAs; 60, 80, 100, 120 kV; 15, 25, 40, 60 projections; 10?, 20?, 40? , 50? sweep angle). With calculi scoring method, the difference in capability of showing various urinary tract calculi within each group of imaging parameters was compared, and the smallest diameter of urolith by digital tomosynthesis was detected. The best imaging parameters will be integrated to estimate the capability of digital tomosynthesis in detection of clinical urolithiasis. Results Compared with the calculus scores from the other imaging parameters within the same group, the calculus scores based on 1.0 mAs, 100 kV, 25 projections and 20? sweep angle were the highest score (all P<0.05), and the corresponding exposure dose was also lower. The scores of the 1.0 mm and 0.5 mm calculi in all images of digital tomosynthesis were low. Conclusions The 1.0 mAs, 100 kV, 25 projections and 20? sweep angle may be most appropriate imaging parameters for digital tomosynthesis in detection of uroliths. However, the capability of digital tomosynthesis is insufficient in detecting those urinary tract calculi less than 1.0 mm in diameter.