A current parameter elastic network regularization inversion method based on spherical harmonic decomposition comprises the following inversion steps of establishing a spherical harmonic function model, and establishing a point P to be measured in a magnetic field and a magnetic field intensity vector value H formula (1) of the point P to be measured; obtaining a magnetic field intensity vectorvalue H formula (2) generated by the line current to be solved at the measuring point according to the ampere loop law; when no magnetic field source exists at the measuring point, obtaining a mode of representing H as scalar magnetic bit; and solving the line current to be solved by adopting a regularization method. The beneficial effects are that external interference and calculation errors is reduced by adopting a hardware arrangement optimization and software algorithm decoupling method to obtain a line current parameter inversion result; and the algorithm based on spherical harmonic decomposition and the regularization calculation method are adopted, the separation of the measured current is realized only by using a mathematical means, the influence of an external interference magnetic field is eliminated, and the measurement precision is improved.