Abstract: It is widely recognized that the function of a protein is dependent on its spatial structure. All kinds of interactions taken place inside the protein are superposed in the space to form a molecular field, which affects the protein function greatly. An algorithm based on linear calibration quantum chemistry theory for fast calculating the molecular field of a protein is presented in this paper. Since the protein molecule is too complex to be computed with the classic quantum chemistry algorithm, we employ the divide-and-conquer strategy to divide the protein into several fragments according to amino acid residue. The computation results on all the fragments are finally integrated by performing interpolation at the overlapped boundary. The whole process is further accelerated by parallel computing based on MPICH. Experimental results demonstrate the effectiveness and efficiency of our approach.