The invention discloses a characterization method for a porous structure of a regenerated cellulose material. The characterization method comprises the following steps: firstly, soaking regenerated cellulose into liquid and oscillating; secondly, carrying out nuclear magnetic relaxation hydrogen spectrum test on the regenerated cellulose treated in the first step; thirdly, carrying out inverse laplace transformation on a nuclear magnetic relaxation attenuation curve obtained by the nuclear magnetic relaxation hydrogen spectrum test to obtain parameters for characterizing the porous structure of the regenerated cellulose. According to the characterization method disclosed by the invention, the relationship that relaxation time (logarithms and horizontal coordinates) is in direct proportion to the content of pores (longitudinal coordinates) can be obtained, therefore, the sizes of the pores can be qualitatively explained; if specific values of the sizes of the pores need to be determined, different formulas are adopted for calculating according to difference of samples. According to the characterization method disclosed by the invention, drying or freeze-drying treatment of samples is not needed, so original states of the samples can be well kept.