The invention relates to a dynamic calibration device of a counter-force roller braking bench based on a hydraulic servo, mainly comprising a hydraulic servo force application device, a buffering shock absorption mechanism, a force transmission beam mechanism, a force measurement mechanism and a support frame mechanism. The invention mainly aims to solve the problem that the traditional counter-force roller braking bench can not be used for evaluating the dynamic response of a braking bed. The dynamic calibration device is arranged on the counter-force roller braking bench to form a force closed-loop control system to provide a force value changed according to an ideal standard force value curve for the calibration of the braking bed, and the standard force value curve is compared with a measuring force value curve measured by the force measurement sensor of the braking bed per se and obtained after being amplified by a filter amplifying circuit to evaluate the dynamic response quality of the braking bed to realize dynamic calibration.