Lacking of local or global extrema in the area of the sea and sky of the image causes the failure of the traditional Bi-dimensional Empirical Mode Decomposition (BEMD). The frequency characteristic of BEMD is analyzed, and the construction method of the high-frequency assisted signal is given. The high-frequency assisted signal is added to the original video image signal, and then we obtain the closest frequency components to the assisted signal of the original signal by subtracting the decomposed intrinsic mode component (IMC) to the assisted signal of IMC. Moreover, the different frequency components of the original signal can be obtained. Solving the problem of lacking of local or global extrema of the maritime image, this assisted signal BEMD is applied to the enhancement of maritime degraded image, and the acquired result is consistent with that of the currently accepted HE’s algorithm.