Saltation bombardment is one of the main dynamic mechanisms of dust emission in arid regions. The kinetic energy of saltated sand directly affects dust emission intensity. However, the sand kinetic energy conversion process and its influence on dust emission is still poorly understood. In this study, we systematically investigated the sand impact energy (E-I), rebound energy (E-R), rebound efficiency (R-E=E-R/E-I) and dust emission flux (F) variation characteristics on Gobi Desert (GD) and Sandy Desert (SD), under different conditions by field wind tunnel experiments. The results show that the E-I, E-R and R-E of saltated sand on the GD are significantly higher than those on the SD for the same wind speed. The F of GD is also larger than that of the SD. The E-I and R-E of GD are 3.2 similar to 4.8 and 3.1 similar to 10.9 times higher than those of SD, respectively, and the E-R is higher by an order of magnitude. The surface properties (i.e., dust content) and the particle size of bombardment sand has a significant impact on the energy conversion process and dust emission. Specifically, the R-E was positively correlated with surface gravel coverage and hardness (exponentially increasing), and negatively correlated with surface dust content (linearly decreasing). The EI of coarse sand (0.5-1 mm) at high wind speed (>12 m.s(-1)) was greater than that of medium sand (0.25-0.5 mm) and fine sand (0.1-0.25 mm), but the E-R and R-E of coarse sand were smaller than those of medium and fine sand, which is consistent with the results that coarse sand has the highest F at high wind speeds. This indicates that the lost energy in the sand energy conversion processes determines the dust emission intensity and is an important driver for dust emission. This energy conversion mechanism provides new theoretical references and perspectives for the construction of dust emission models.