The demagnetization, spin switching, and spin transfer in magnetic molecular systems can be theoretically achieved via the laser-induced Λ process. In the present work, both quantum chemistry ab initio calculations and our self-written programs are adopted to investigate the spin-transfer behavior of the magnetic molecular ions with linear configuration. It is shown for the first time that the Λ process based ultrafast spin transfer can be achieved in a linear two-magnetic-center molecular ion [Fe-O-Co]+, and the fidelity of the population transfer exceeds 90%. The present theoretical prediction shows that the magnetocrystalline anisotropy of a molecular system can be enhanced by properly adjusting the direction of the applied magnetic field, which is shown to be a better way to improve the spin-transfer ability of the molecular system than by increasing additional bridging atoms since it could avoid the complexity of the latter situation in practical applications. At the same time, the present spin-transfer scenario indicates that the fidelity of the population transfer could also be evidently increased.