The invention relates to a 
contactor diagnosis / total 
voltage acquisition circuit of a vehicle 
power battery. The circuit comprises a sampling circuit and a detection 
branch, a first end of the detection 
branch is connected to one end, far away from a 
power battery, of a current to-be-detected 
contactor, and a second end of the detection 
branch is connected to one end, close to the 
power battery, of a non-current to-be-detected 
contactor; a first switch connected with the first end, a second switch connected with the second end, a plurality of divider resistors and a reference 
voltage source used for providing forward bias for sampling points of the sampling circuit are arranged in the detection branch; the first switch, the reference 
voltage source, the first divider 
resistor, the third divider 
resistor and the second switch are sequentially connected in series. The reference 
voltage source and the first divider 
resistor are connected in series and then connected with the second divider resistor in parallel. A sampling point of the sampling circuit is connected with a series connection point of the first divider resistor and the third divider resistor. The circuit not only realizesthe diagnosis of the contactor, but also can acquire the total voltage of the contactor, thereby greatly reducing the measurement difficulty of the 
terminal voltage of the contactor.