Abstract: The existence of the lacking region in the Doppler weather radar velocity field is one of the most important factors impacting the accuracy of velocity products. An iterative filling method based on the VAD technique is presented in detail under the assumption of the actual wind field of linear distribution. A filling test is conducted for the artificially created random discontinuous cumulative 10°-180° missing gap as well as the continuous cumulative 10°-180° gap according the type of lacking area, based on the observational Doppler data. The analysis shows that the method is suitable for the random discontinuous cumulative gap within 180°and the continuous cumulative gap up to 110°. The average absolute error is in about 2 m/s compared with the original data. The linear interpolation method and the iterative method are also compared with each other under the two methods' prerequisite conditions met concurrently. The results show that the accuracy of the two methods are creditable. Relative to the sensitivity in the positive and negative turn of velocity data in linear interpolation method, iterative method should have a broader application.