Abstract: The application of a current senor in a feedback circuit is introduced in this paper and this sensor is CB0.1-CNS6B1. In order to make the variation of the load current smaller than 1% when the load resistance varies from 33.6 to 36.4 Ω, the current sensor is incorporated in the circuit. But due to the sensor’s adding, the 1 Hz’s oscillation emerged in this circuit. Based on the identification of the sensor’s model, the key factor of this problem was found through the simulation analysis. Finally, the oscillation problem in this circuit was solved with the feedback control method, thus achieving the required specification.