Photoelectron spectroscopy in intense laser fields has proven to be a powerful tool for providing detailed insights into molecular structure. The ionizing molecular orbital, however, has not been reconstructed from the photoelectron spectra, because its phase information is difficult to access. Here, we propose a method to retrieve the phase information of the ionizing molecular orbital. By analyzing the interference pattern in the photoelectron spectrum, the weighted coefficients and the relative phases of the constituent atomic orbitals for a molecular orbital can be extracted. With this information, we reconstruct the highest occupied molecular orbital of N₂. Our work provides a reliable and straightforward approach for reconstructing molecular orbitals with the photoelectron spectroscopy.