Based on the perfect transfer theory of single qubit information in spin chain, the influence of two kinds of low-intensity magnetic fields independent on time acting on N=3 spin chain on single qubit quantum information perfect transfer is investigated. The Hamiltonian including magnetic field system is diagonalized, and the evolution operator effect is taken into account. Results show that a constant low-intensity magnetic field with uniform space and independent on time has no influence on fidelity of information transmission. The low-intensity magnetic field independent on time which is symmetry to the center of the spin chain and contrary in direction affects conditions for perfect transfer of quantum information. The stronger the magnetic field is, the shorter the time needed will be to realize perfect transfer.