Abstract-Space-time antijamming problems cause widespread concern recently in global navigation satellite system. Space-time adaptive procession (STAP) is an effective method to suppress interference signals, which contains two adaptive filters, i.e., spatial filter and temporal filter, and the array pattern can be automatically optimized by adjusting the weights obtained from a prescribed objective function. However, mismatch may occur between adaptive weights and data, due to the change of the interference location when receiver is shaking. In this case, the performance of STAP will degrade dramatically. To solve this problem, an effective nulling widen method based on uniform circular array (named as UCA-NW algorithm) is proposed for space-time antijamming. Through this method, an extension matrix is given to modify the covariance matrix, and the formed null can be broadened from azimuth angle and pitch angle, respectively. Thus, this algorithm can suppress interference signals effectively when the receiver is shaking, and the width of nulls can be controlled easily. Simulation results are presented to verify the feasibility and effectiveness of the proposed algorithm.