In order to study the characteristics of slope runoff and sediment yield on the cone shaped engineering accumulation, a self-made platform was used to simulate the three-dimensional pyramidal engineering accumulation, and indoor artificially simulated rainfall experiments with different rainfall intensities (1.0, 1.5, 2.0 and 2.5 mm/min) were carried out. The heavy soil in Guanzhong area was used as test material, and different mass percentages of gravel (0, 10%, 20%, 30%, and 40%) were set. The results showed that: (1) The runoff rate and flow velocity increased rapidly first and then slowly increased to the stable with the time trend, the rainfall intensity and gravel content both had significance influence on runoff rate and flow velocity, and the rainfall intensity played a decisive role; (2) The mean runoff rate and flow velocity had very significant positive correlation with rainfall intensity and very significant negative correlation with gravel concentration; (3) When the rainfall intensity was 1.0 mm/min, the erosion rate first increased rapidly and then tended to be stable, when the rainfall intensity was greater than 1.5 mm/min the erosion rate showed a trend of continuous growth, while when the rainfall intensities were 2.0 and 2.5 mm/min, the erosion rate increased abruptly in the middle and late stages of rainfall; (4) The total amount of erosion showed an exponential increase trend with the increasing of rainfall intensity and a logarithm decrease trend with the increasing of gravel content.