Abstract: To reveal the seismic source mechanism of strong dynamic loads and the corresponding law of seismic source parameter in the deep mining, the distribution characteristics of strong dynamic loads and the seismic source mechanism during the mining period were analyzed by taking the working face of Gucheng Mine 3105 as the engineering background. The time-frequency characterization of different types of strong dynamic loads was carried out with the method of HHT, and the seismic source parameter of the three types of dynamic loads was quantitatively calculated, which reveals the energy release characteristics and rupture patterns of different types of dynamic loads. The energy release characteristics and rupture modes of different types of dynamic loads are revealed. The results show that the strong dynamic loads can be divided into roof motion type, coal column instability type and fault misalignment type. It is found that the dynamic load in the fault area changes the stresses on both sides of the fault and causes compression damage; the dynamic load in the roof area is affected by the roof damage mechanism and mainly causes compression damage and shear damage; and the dynamic load in the coal pillar area mainly causes compression damage. The inclination angle of fault-type strong dynamic load mainly ranges from 30° to 45°, that of roof-type strong dynamic load from 10° to 65°, and that of coal pillar-type strong dynamic load from 40° to 50°, respectively. The three types of dynamic load waves differ greatly in frequency distribution and energy distribution, and the energy release characteristics of the rupture of their seismic sources are also different. The marginal spectrum of the roof-type strong dynamic wave shows a single-peak distribution, and the frequency is mainly concentrated in 50−90 Hz; the marginal spectrum of the fault-type strong dynamic wave shows a double-peak distribution, and the frequency is mainly concentrated in 0−50 Hz; and the marginal spectrum of the coal-pillar-type strong dynamic wave shows a broadband spectrum distribution, and the frequency is mainly concentrated in 10−100 Hz. The coal-pillar type strong dynamic wave has the largest seismic moment, followed by roof type, and the smallest one of the fault-type. In the case of the same radius of the seismic source, the inelastic deformation of the fault-type dynamic load leads to the largest volume increase, followed by the coal-pillar-type strong dynamic load, and the roof-type strong dynamic load has the smallest scale. The findings can provide some theoretical references for the prevention and control of sub-sources in mines of rockburst tendency.