The invention relates to a design method for a sea clutter inhibition curve of a marine radar based on wavelet transformation, and belongs to the technical field of signal processing of the marine navigation radar. Echo data of the radar in the measuring range is decomposed via discrete wavelet transformation, a high-frequency coefficient is zeroed, and a high-level approximate part is used to estimate power level of sea clutters. A corresponding adjustable sea clutter inhibition curve is calculated according to a range parameter and a sea clutter inhibition intensity parameter, and the estimated power level of the practical sea clutters is overlapped with the adjustable sea clutter inhibition curve to obtain a general sea clutter inhibition curve. The inhibition curve design method is highly adaptive to a traditional sea clutter inhibition method relied on statistical characteristics, it is not required to predict distribution which the power level of background clutters obeys in advance, the method has a good inhibition effect for near sea clutters, and the problem that sea clutters surrounding the circular center of a radar screen are hard to eliminate is overcome; and the design method is flexible to use, and includes different inhibition levels, so that a user can carry out sea clutter inhibition of different levels according to practical sea-condition information.