Many methods and models have been used to construct crustal movement velocity fields, including Least Squares Collocation, multi-surface functions, spherical harmonics methods, spherical discontinuous deformation analysis, and finite element methods, all of which have certain premise conditions or application scope.Based on the Euler vector, we put forward a new particle swarm optimization (PSO) algorithm from which block motion and strain tensor parameters can be determined by inversion, and then a regional crustal movement velocity field can be constructed.Simulation test results showed that this improved PSO is stable and effective. When the iteration reached 20 times, the improved PSO results were close to their optimal values, while the other two algorithms continued to search.The precision of the velocity field constructed by this method is much higher than that from linear and nonlinear PSOs.A comparison of the effectiveness and lack of bias of the displacement calculated by different methods indicated that the accuracy of the velocity model calculated by the improved PSO was the highest, and the variance and mean value of its residuals were much smaller.Based on GPS observational results from the northeastern margin of the Tibetan Plateau from 1999 to 2013, for which coseismic disturbance has been considered on the basis of block division and model identification evaluated by unbiased and effectiveness rules, the crustal movement velocity field was determined using the improved PSO.The residual characteristics that closely followed a normal distribution indicated that the velocity field calculated by the improved PSO was reliable and without systematic error.A comparison with the results calculated by Least Squares Collocation was performed, which indicated that the new PSO algorithm effectively and accurately established the crustal movement velocity field.From the constructed velocity field, a significant difference can be seen in how the northeastern margin of the Tibetan Plateau crust moves;the velocity decreases from south to north with clockwise rotation.The NE motion is blocked by the relatively stable Alashan block, which is creating mountain uplift and basin subsidence in the region.