Oxidant was prepared by the method of electrochemistry in situ leaching gold from refractory gold ores under the ultrasonic-aided and un-ultrasonic-aided conditions. Result show that the application of ultrasonic condition greatly increases the leaching rate and shortens the reaction time while the conventional cyanide method is adopted, the gold leaching rate after leaching 24 h is only 25% of the refractory gold ores. In the equal conditions, under the un-ultrasonic-aided in situ leaching conditions the leaching rate is 54.84% after leaching 6 h, whereas under the ultrasonic conditions the leaching rate grows to 90.68% after leaching 6 h. Otherwise, through comparison the X-ray diffraction patterns of ores and slag it is found that there exists element sulfur on the surface of un-ultrasonic-aided electro-chlorination leaching slag, and no sulfur on ultrasonic surface of the slag. And the effect of ultrasonic-aided condition on the electrode reaction and the mechanism of ultrasonic-aided leaching gold from refractory gold ores are analyzed.