Fuelling and particle control are important topics for ITER physics. Because of the low efficiency of gas puffing and the high cost of pellet injection, other methods were explored in the last decades. A new method for plasma gas fueling, the pulsed supersonic molecular beam injection (SMBI) was successfully developed at Southwestern Institute of Physics in China and applied on HL-1M and HL-2A devices in recent years. SMBI possesses a great advantage over conventional gas puffing, mainly due to the higher instantaneous fueling intensity and speed, smaller spread of velocity and angular distribution of the particles than the latter. In this paper, we report the experiment results of the SMB injected from LFS and HFS in HL-2A device, the effect of  Δ B on SMB penetration is considered. During SMB injection in Tokamak, there is a rapid movement of the ablation beam substance towards the outward major radius R direction. The favorable injection from the high field side in order to promote deeper fuel penetration can be obtained. The motion has been attributed to a vertical curvature and  Δ B drift current induced inside the ionized ablated SMB particles by the 1/R toroidal field variation. The uncompensated vertical drift current inside the weakly diamagnetic ablation particles will cause charge separation at the plasma edge. The resulting electrostatic field induces the  E×B  drift to the large R side of the torus.