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A method for manipulating molecules without suitable electronic properties to be viable candidates for laser cooling is described. Only a few natural molecules have a highly diagonal Franck–Condon factor (FCF) for the laser cooling scheme. Thus, we manipulate the FCFs by using an electric field identified by an optimized method based on linear regression. The details and the validity of the method are demonstrated using the CsH molecule. The different angles between the electric field and the molecular axis are considered, and the potential energy surfaces dependent on the electric field and angle are constructed. The vibrational energies and FCFs dependent on the angles are obtained, and the corresponding laser cooling schemes relative to the angles are built, which induce the accumulated FCFs of each scheme to exceed 0.999. The schemes can exert work at the angle between the molecular axis and the electric field is 1080° with five pumping lasers with center wavelengths of 473.74, 499.58, 527.72, 540.22, and 571.62 nm. In principle, the present method can be extended to any diatomic molecules without highly diagonal FCFs under natural conditions, providing a theoretical basis for studying physical and chemical problems involving cold molecules.