Abstract: A global ocean acoustic forecasting system (FIO-GOAFS) for high performance computer is designed and established by combining acoustic propagation models with the surface wave-tide-circulation coupled ocean model with 0.1° resolution developed by the First Institute of Oceanography, MNR. Sound velocity profiles are calculated with temperature, salinity, and pressure for the diagnosis of underwater acoustic environment characteristic, then the ocean model and underwater acoustic propagation model are coupled. Combined with geo-acoustic model (seafloor topography and substrate parameters), the diagnosis of underwater acoustic environment characteristics and the prediction of underwater acoustic field are realized. Ocean model simulated the sound velocity and wave height parameters, and geo-acoustic model provides the parameters including seafloor topography, sound velocity, density, and attenuation of substrate. By calling the ocean-acoustic coupled module, the seafloor topography and ocean environmental parameters as well as sound propagation path are thus extracted to realize the effective connection between the ocean model and the acoustic model. The parallel operation of the global ocean acoustic forecasting system mainly includes the parallelism of frequency point and azimuth angle in sound field calculation and the parallelism of geospatial region in acoustic forecasting. Finally, the seasonal and spatial variation of underwater acoustic environment characteristic and sonar detection range in the global ocean are predicted and analyzed by using the forecasting system, these results provide useful reference for the design, operation, and underwater applications of modern sonar.