The tensile test of TC4 alloy was carried out in the presence of a high pulsed magnetic field. The effects of magnetic induction intensity (B=0T, 1T, 3T, 5T) on the elongation, phase characteristic, crystal structure and dislocation density were investigated. The results show that the imposed magnetic field has enhanced the elongation. At 3T the elongation arrives at the maximum of 12.41%, which is enhanced by 23.98% compared to that of 0T sample. The 3T parameter is ascertained as a traverse point from increase to decrease tendency. Furthermore, the magnetic field has accelerated the phase transformation from β to α together with the orientation preference of crystal plane along the slipping direction. As for the dislocation density, it exhibits as the first increase followed by the falling tread. At 3T it arrives at the utmost. It is analyzed that the phenomenon is attributed to the enhancement of dislocation strain energy in the presence of magnetic field. Next, the magnetic field promotes the transition from singlet to triplet state. At last the inevitability of optimized 3T parameter is further discussed in the quantum view.