1. An MR imaging method for radial trajectory, comprising: a first step of calculating sensitivity information S from pre-acquired data through an MRI device; a second step of receiving an input of a signal g that is radially sampled through parallel coils in the MRI device and obtaining two offset-adjusted signals gL′ and gU′ through increasing/decreasing a boundary value; a third step of receiving an input of an initial image value f 0 and obtaining two offset-adjusted signals fL 0 ′ and fU 0 ′ from the an initial image value f0; a fourth step of obtaining projection signals PL and PU using the sensitivity information S obtained in the first step and the two offset-adjusted signals fL 0 ′ and fU 0 ′ of the initial image value obtained in the third step; a fifth step of obtaining coefficients real_cL, imag_cL, real_cU, and imag_cU using the sensitivity information S obtained in the first step, the offset-adjusted signals gL′ and gU′ obtained in the second step, and the projection signals PL and PU obtained in the fourth step; a sixth step of reconfiguring an image by multiplying the coefficients real_cL, imag_cL, real_cU, and imag_cU obtained in the fifth step by the offset-adjusted signals fL 0 ′ and fU 0 ′ of the initial image value obtained in the third step, and acquiring a first target image f 1 through combination of the images; and a seventh step of replacing the input value in the third step by the first target image f 1 obtained in the sixth step and repeatedly performing the third to sixth steps until a final target image is acquired.