The invention provides a field calibration device of a plumb line displacement system. The field calibration device comprises a top plate, a slide platform, a first digital readout micrometer, a second digital readout micrometer and a clamp, wherein a hanging device is arranged at the bottom of the top plate; the slide platform comprises a first slide layer, a second slide layer, a third slide layer, a middle layer and a rotary layer; the first slide layer is fixedly connected with the top plate; the first slide layer is connected with the second slide layer through a first steel ball linear rail and a first spring; the second slide layer is connected with the third slide layer through a second steel ball linear rail and a second spring; the third slide layer is fixedly connected with the middle layer; the middle layer is connected with the rotary layer through a rotary shaft; the first digital readout micrometer is arranged at the outer side of the second slide layer and the second digital readout micrometer is arranged at the outer side of the third slide layer; the top of the clamp is connected with the bottom of the rotary layer; and a clamping part for clamping a plumb line displacement system to be calibrated is arranged at the bottom of the clamp. With the adoption of the field calibration device of the plumb line displacement system, field bidirectional calibration can be carried out on the plumb line displacement system to be calibrated.