The invention provides a mixed gas breakdown voltage detector, and a mixed gas breakdown voltage prediction method using the same. The mixed gas breakdown voltage detector includes a high voltage supply generator and a plurality of mixed gas breakdown voltage detection units, wherein each mixed gas breakdown voltage detection unit includes a gas sealing system, a capacitance-resistance divider, a switch, a switch motion control system and an oscilloscope; the positive and negative electrodes of the gas sealing system are respectively connected with positive and negative output ends of the high voltage supply generator; a connecting line between the gas sealing system and a positive output end of the high voltage supply generator is connected with the switch motion control system; a connecting line between the gas sealing system and the switch motion control system is connected with the switch; a high voltage end of the capacitance-resistance divider is connected with a connecting line between the high voltage supply generator and the switch; and a low voltage end of the capacitance-resistance divider is connected with the oscilloscope. The mixed gas breakdown voltage detector builds parallel mixed gas breakdown voltage detection units to detect the breakdown voltage under different ratios, thus improving the detection efficiency, and establishes a model for supporting vector machine regression prediction to predict the breakdown voltage, thus reducing the workload of a breakdown voltage experiment.