We study the strong-field tunneling ionization of molecules using the molecular quantum trajectory Monte-Carlo model and the partial Fourier-transform approach for molecules. From both models, we extract the phase structure of the tunneling wave packet of aligned molecules, which depends on the initial transverse momentum. We extend the partial Fourier-transform approach to calculate the photoelectron momentum distributions of diatomic molecules. We further calculate the alignment-dependent ionization rates by both models. These semiclassical models for strong-field ionization of molecules are particularly useful in the study of photoelectron diffraction and photoelectron holography.