The electromagnetic scattering of composite objects with large size is calculated by the Method of Moments(MoM). In order to calculate the electric scattering of the electric three-dimensional composite target efficiently and quickly, a new method is proposed, which combines the Adaptive Cross Approximation(ACA) algorithm and the Multi-Level Fast Multi-pole Algorithm(MLFMA) to accelerate the MoM. Among them, MLFMA is utilized to accelerate the self-interaction of objects; ACA is utilized to accelerate the coupling interaction between the object and other targets. The hybrid algorithm proposed in this paper can reduce the computational memory, reduce the filling time of the impedance matrix, and accelerate the matrix vector multiplication without affecting the accuracy of the calculation when calculating the composite target electromagnetic scattering. Numerical examples show that the proposed fast algorithm can be more efficient than the traditional method under the premise of ensuring the accuracy of electromagnetic scattering calculation.