Using fractal dimension or one of other fractal characteristics to detect targets in sea clutter, it is often difficult to distinguish at low signal-to-clutter ratios. To solve this problem, a new method for target detection in sea clutter based on combined fractal characteristics is proposed. The detection process is divided into two stages: coarse detection and fine detection. When the fractal spectrum dimension of the detection unit is obvious, in the rough detection stage, the corresponding processing is carried out to achieve the target existence decision; when the fractal spectrum dimension characteristic is not obvious, the fractal model fitting error and the fractal dimension change quantity are used as characteristic quantities, and the comprehensive fuzzy membership degree is adopted to carry out the fine target detection. Verified by X-band radar real data, the results show that the proposed method can greatly enhance the detection accuracy of weak targets within sea clutter.