The invention discloses a method and a device for real-time simulation of a steady-state sound field space in a marine environment. The method comprises: receiving original sound source data input bythe user; establishing the background model of the sound field space in the marine environment; determining a steady-state sound field space matrix in the marine environment according to the background model of the sound field space in the marine environment, the original sound source data, a sound trajectory equation under a non-coplanar condition of the sound ray and the sound velocity gradientvector, a eikonal equation of a discrete process, and a group march method GMM; outputting the steady-state sound field space matrix in the marine environment. The method utilizes the sound ray tracking technology of the steady-state sound field space to obtain the sound field information in the whole marine environment of the region of interest under the requirement of high precision, and the amount of calculation required is low.