The invention discloses a double-main-break control system of a motor vehicle of a centralized power electric motor train unit. A first pantography PG1 and a second pantography PG2 are connected with an overhead contact system, a high voltage lead led out from the first pantography PG1 is connected with a first main circuit breaker QF1 and a first high voltage potential transformer TV1 in sequence, and a secondary output line of the first high voltage potential transformer TV1 is connected to a contact point 11 end and a 12 end of a network voltage conversion relay KD1; and a high voltage lead led out from a second pantography PG2 is connected to a second main circuit breaker QF2 and a second high voltage potential transformer TV2 in sequence, a secondary output line of the second high voltage potential transformer TV2 is connected to a contact point 13 end and a 14 end of the network voltage conversion relay KD1. The double-main-break control system of the motor vehicle of the centralized power electric motor train unit has the beneficial effects that the reliability of application of a locomotive is improved, and the two main circuit breakers can automatically control closure of main break on the same motor vehicle.