The invention discloses a calibration device for a direct-current differential transformer type displacement sensor. The device comprises a base, a fixed device, a mounting plate, a grating ruler, anadvancing and retreating lead screw, a control system and a digital multimeter. A displacement sensor to be calibrated is fixed on the fixed device. The mounting plate is connected to an iron core ofthe displacement sensor, and the mounting plate is also connected to the grating ruler and the advancing and retreating lead screw. The advancing and retreating lead screw is further connected to thecontrol system. The digital multimeter is connected to the displacement sensor. During use, the control system drives and controls the advancing and retreating lead screw according to a calibration point of the displacement sensor to be calibrated, the mounting plate is linked with the advancing and retreating lead screw, the grating ruler reads the displacement amount of the advancing and retreating lead screw, the output voltage of the displacement sensor is read through the digital multimeter, so that calibration is realized. The calibration method and an operation process can be simplified, and the calibration efficiency is improved. The rotation output of a stepping motor is controlled so that an input of the displacement sensor is controlled, and the semi-automation requirement is met. The mounting plate is detachable and can be assembled and matched for multiple times, so that the device is more universal.