We study a biorthogonal multiresolution time-domain (bi-MRTD) method and use it to analyze electromagnetic scattering properties and compute radar cross sections (RCS) of three-dimensional objects. Compactly supported biorthogonal Cohen-Daubechies-Feauveau(CDF) wavelets with rigorous interpolation property are employed as spatial basis functions to expand the field components. A rigorous three-dimensional calculation formula is derived by applying the wavelet-Galerkin sampling method. Dispersion properties of the bi-MRTD methods are studied. Anisotropic perfectly-matched layer (APML) is chosen to truncate the computational space. The incident wave is introduced by using the total-field/scattered-field (TF/SF) technique. Theoretical analyses and experimental results show that the bi-MRTD method can save considerable computational resources without loss of accuracy in comparison with FDTD and the MRTD method based on non-compactly supported Battle-Lemarie (B-L) wavelets.