The present invention relates to an indirect measurement method of filter branch current, belonging to the technical field of the measurement of a filter. The Indirect measurement method comprises thesteps of (1) determining a topological structure and circuit parameters of a filter, (2) designing a digital filter according to the topological structure of the filter, wherein the digital filter represents a transfer function of branch current which needs to be measured and known current in the filter, and determining each part parameter of the digital filter according to the circuit parametersof the filter, and (3) calculating the branch current which needs to be measured according to the digital filter and the known current in the filter in the step (2). According to the indirect measurement method, the adding of a current measurement point in the branch which needs to be measured, the hardware modification of the filter is avoided, the cost is greatly reduced. The method has great flexibility and can be applied to filters with different structures, only the change of the type and parameters of the digital filter according to requirements is needed, and the measurement requirements of different filters and different branch current are satisfied.