The effect of single-particle droplet splash on sediment incipient motion was investigated through indoor simulated rainfall test. Four surface slopes (0, 15°, 25°, 35°), four particle sizes of uniform sand (0.098-0.104 mm, 0.104-0.5 mm, 0.5-0.78 mm, 1-1.4 mm) and droplets with equivalent diameter of 4.5 mm were designed in the test. The designed water-elastic water balloons made of super absorbent resin were used as the control group. The results showed that the changes of particle diameter and slope had a significant effect on particle's initiation, and the splasher droplets were of great significance to droplet splash erosion. With the increase of particle diameter, the sediment incipient motion gradually changed from the joint action of droplet impact and sub droplet splash to the transfer of droplet impact kinetic energy, supplemented by splash carrying. When the particle diameter was the same, the increase of slope led to the non-equilibrium of splashed sand particles, and the amount and displacement of particle splashing under the slope increased with the increase of slope. The greater the slope, the greater the gap between the splash erosion depth of the particles below and above, resulting in the loss of support of the particles above, overall instability and collapse, and micro landslide. When the particle size was the same, the width depth ratio of the water-bomb splash pit was significantly smaller than that of the droplet splash pit with the same diameter, and the amount of droplet splash was much larger than the number of particles started under the direct impact of the water bomb. The drag of sub droplets affected the particle's initiation significantly.