Abstract: To investigate the explosion performance of ammonium-amine explosives under deep-water hydrostatic pressure conditions, an experimental simulation device for blasting charges in a deep-water hydrostatic pressure environment was designed. An optical microscope was used to observe the microscopic bubble changes in the explosive after exposure to atmospheric pressure and hydrostatic pressures of 0.1 MPa, 0.2 MPa, 0.3 MPa, and 0.4 MPa for 1 hour followed by pressure relief and recovery. Fiji image analysis technique was employed for microscopic characterization of the size distribution of sensitizing bubbles. The density of the explosive under hydrostatic pressure was measured. The detonation velocity of the explosive in a PVC charge tube with an outer diameter of 40 mm was tested under atmospheric pressure, after pressure relief, and under hydrostatic pressure. The results indicate that the deep-water hydrostatic pressure environment has a significant effect on the performance of ammonium-amine explosives. For the explosive after pressure relief and recovery, when the pressure ranges from 0 to 0.2 MPa, the number of microscopic bubbles increases with increasing pressure, leading to an increase in effective "hot spots", and the detonation velocity increases from 4313 m·s⁻¹ to 4621 m·s⁻¹. When the pressure exceeds 0.2 MPa, bubbles coalesce and merge, reducing the number of effective "hot spots", and at 0.4 MPa, the detonation velocity decreases to 4072 m·s⁻¹. For the explosive detonated under hydrostatic pressure, as the pressure increases from 0 to 0.4 MPa, the explosive density increases from 1.02 g·cm⁻³ to 1.34 g·cm⁻³, following the relationship ρ = 0.47P^0.43 + 1.02. The detonation velocity increases from 4313 m·s⁻¹ under atmospheric pressure to 4448 m·s⁻¹ at 0.1 MPa, decreases to 3412 m·s⁻¹ at 0.3 MPa, and results in failure to detonate at 0.4 MPa. The ammonium-amine explosive exhibits a certain resistance to deep-water hydrostatic pressure and demonstrates good recovery after pressure relief.