The sensitivity of Wheatstone bridge is a major factor affecting the accuracy of resistancemeasurement.The relationships between the sensitivity of Wheatstone bridge and power supply electromotiveforce ,bridge arm resistance and bridge arm ratio are explored. Theoretical analysis shows that, when the totalcurent of the circuit remains constant, the larger the bridge arm ratio, the lower the Wheatstone bridgesensitivity and the lower the resistance measurement accuracy.ln addition,when the bridge arm ratio remains unchanged and the total current of the circuit is small,the greater the total current,the higher the Wheatstonebridge sensitivity and the higher the resistance measurement accuracy.The experimentally measured dalaconfirms the conclusions obtained from the theoretical analysis.