In order to systematically investigate variation of splash detachment under soybean cover and to establish a simple practical model, with which to evaluate effects of soybean crop on splash detachment, rainfalls, 40mm h^-1 and 80mm h^-1 in intensity, were simulated indoors for measuring thoughfall intensities and splash detachment rates under soybean canopy at different growth stages, analyzing relationships of splash detachment rate and throughfall intensity with LAI, and exploring spatial distribution of splash detachment rates under soybean canopy. Results show that compared to bare soil, the field with soybean was 62.85% and 60.74% lower in average splash detachment rate of the whole growth period under rainfall, 40 mm h^-1 and 80 mm h^-1, in intensity, respectively. The average splash detachment rate under soybean canopy displayed a significant trend of rising with LAI and rainfall intensity. The splash detachment rates at various monitoring points were significantly affected by the throughfall intensities at the corresponding positions, especially under the rainfall, mm h^-1 in intensity, increasing with throughfall intensity. The spatial distribution of splash detachment rates corresponded to a certain extent with the distribution of throughfall under soybean canopy. In another word, in places where throughfall under canopy concentrated, splash detachment would increase to a certain extent, thus leading to uneven distribution of splash detachment rates under canopy. Therefore, throughfall is the major source of energy triggering splash detachment and affecting its distribution. The splash detachment model proposed in this study could provide some theoretical support for soil erosion control and effective use of irrigation water on slope lands.