The invention relates to a control circuit of powder feeder for hypersonic flame spraying, comprising a first potentiometer, a first speed control panel, a first voltmeter, a first power tube, a second potentiometer, a second voltmeter, a second motor, a second speed control panel, a second power tube, a first switch, a second switch, a first electromagnetic valve, a second electromagnetic valve, a transformer, a first motor and a power strip. The first motor and the second motor allows two feeding branches to be controlled; compared with the traditional single-channel feeding way, the feeding way using the two motors has the advantages that feeding efficiency is improved, the single device is used for two hypersonic flame spraying devices, the production cost is lowered, a replacement function is good, if one feeding branch has a control fault, the other feeding branch can be controlled instead, and smooth spraying is guaranteed.