The invention discloses a device for testing a current sensor, and the device comprises a sensor fixing mechanism, a linear DC power supply, and an oscilloscope. The interior of the sensor fixing mechanism is provided with a fixing device, and the lower end of a current fixing device is provided with a support rod. The support rod is connected with a sliding rod, and the sliding rod is slidingly connected with a fixed rod. A first spring is disposed between the fixed rod and the support rod, and the first sleeve sleeves the sliding rod. The lower end of the fixed rod is fixedly connected witha support plate, and the lower end of the support plate is provided with a lifting device. The linear DC power supply is used for providing an output current, and the oscilloscope, a signal generator,a power amplifier and a load resistor are used for testing a current sensor, and the current sensor is disposed in the sensor fixing mechanism. During the testing of the current sensor, the device reduces the interference caused by the conductive dust to the testing, and enables the testing result to be more accurate. A DC line passes through a through hole, a fixed sleeve and a coil of the current sensor, thereby preventing the jitter of the DC line from affecting a testing result, and enabling the testing to be more precise.