Abstract: It is very important for mine power supply system to know the level of power harmonic in AC side of mine DC hoisting system.In this paper,firstly,modelling of DC hoisting system was built and simulated under Matlab/Simulation in order to know the influence of load change in the DC side on harmonics in AC side theoretically.Secondly,the harmonics of a practical mine DC hoisting system was measured and analyzed.The measurement result showed that the harmonic current of the eleventh exceeds allowed value but harmonice voltage does not exceeds the allowed value when large bell run in full load.Finally,the factors of AC power side harmonics and suitable measurement were given.