In allusion that the relationship between the harmonic current estimated by ICA and the harmonic source voltage is not fixed, a multi-harmonic source localization method based on independent component analysis (ICA) algorithm and mutual information (MI) theory is proposed. ICA algorithm is applied to estimate the harmonic currents. According to the relevant information between the estimated harmonic current and bus voltage, MI theory accurately locates harmonic sources. PSCAD simulations were made to locate multi-harmonic sources in the IEEE 14 bus system. Results show that this approach can accurately locate multiple harmonic sources without knowledge of the network parameters.