The invention provides a wind tunnel flow field start and stop damping device. The device comprises a translational motion plate, a connecting rod, a ball screw, a servo motor, a box, a wall plate and a sliding block connecting piece. The box is arranged above the wall plate. The servo motor is fixed to one end of the box. The servo motor is in shaft connection with the ball screw at the other end of the box through a coupler. A crank link structure is adopted in the connecting rod, one end of a crank link is connected with a nut on the ball screw through a hinge, and the other end of the crank link is connected with the translational motion plate through a hinge. The translational motion plate and the wall plate are kept parallel. The provided damping device has the beneficial effects of being compact in structure and good in dynamic performance, installation and usage can be conducted in a wind tunnel with the limited space, impact loads caused to a model and a balance from the starting and stopping moment of the flow field can be well restrained, and the test data collection accuracy is improved.