The utility model relates to a device for measuring difference in electrode potentials of straight pulled single crystal furnace, which comprises a shell body and a resistance which is respectively connected with an anode of a heating electrode and a cathode of an electrode, wherein one end of the resistance is earthed, and a voltmeter is respectively connected between the anode of the electrode and the ground and the cathode of the electrode and the ground in parallel. The power supplies of the voltmeters are connected with a 25V working power supply. The device has beneficial effects that the structure is simple, the cost is low, and the device can be used for accurately judging the alarm of 'Electrode Earthing Failures' in time, thereby reducing the loss caused by earthing failures.