The invention discloses a sea level essential factor SAR original data simulation method based on an inverse Omega-K algorithm, comprising steps of utilizing an inverse Omega-K algorithm to simulate a sea level scene on the basis of a complex signal two-dimension frequency domain, performing simulation on the SAR original data on the basis of the SAR complex signal two dimension frequency spectrum targeting the sea wave and the sea flow, and utilizing a batch processing simulation mode to cope with the space variance characteristic of the radial speed of the large scale sea wave track, wherein sea essential factor SAR original data obtained through simulation comprises various sea level modulations (inclination modulation, hydrodynamic force modulation, wave track radial speed modulation and speed random distribution modulation in a pixel unit) and sea flow speed information, and the SAR image can present speed beaming effect after sea surface essential factor SAR original data obtained through simulation is imaged through focusing. Compared with the two dimension time-domain sea level essential factor SAR original simulation method, the invention is easy to implement and is small in operation.