Aiming at the demand for non-intrusive measurement of dynamic characteristic parameters in HVDC contactors, as well as the limited adaptability and transferability of short-time analysis methods across different contactor models, a measurement method based on subband averaging kurtogram and time-reassigned multisynchrosqueezing transform (TMSST) is proposed. First, a combination of sliding window framing and dualtree complex wavelet packet transform (DTCWPT) is applied to preprocess the closing acoustic signal of the contactor. Multiple wavelet subbands are obtained and rearranged, and the average kurtosis is calculated to construct the subband averaging kurtogram. The subband with the highest kurtosis is selected as the optimal frequency band for signal reconstruction, enhancing the effective collision-induced impact components. Subsequently, TMSST is employed for time-frequency representation and energy concentration of the collision impact events. The time-frequency coefficients corresponding to the peaks in the time-frequency envelope spectrum are used to characterize the impact features, enabling precise localization of the impact instants of the movable and stationary contact collision and the armature collision, and accurate measurement of the key dynamic characteristic parameters of the contactor, such as closing time and overtravel time. To evaluate the effectiveness of the proposed method, a dynamic characteristic testing system is established, and experimental tests are conducted under various contactor models and sensor layouts. Results show that the proposed method achieves high measurement accuracy in characteristic parameter estimation for various types of HVDC contactors, with both mean absolute error (MAE) and root mean square error (RMSE) maintained within 0.35 ms. Compared with the shorttime analysis methods, the average MAE and RMSE are reduced by over 39%. In addition, it exhibits low dependence on the sensor layout and strong generalization capability across different contactor types, demonstrating considerable potential for engineering applications.