One of the important reasons for severe infestations of Locusta migratoria tibetnsis Chen was that the locust nymphs have the habit of aggregation migration. In order to elucidate the mechanism of migration of locust nymphs and to provide a scientific basis for the control of this pest, we applied visual tracking to measure the speed and direction of movement of the migratory locust nymphs in the fields. Then we set a self-propelled particle model (SPP) to simulate the migratory behavior of locust nymphs, and the characteristics of migration were analyzed. The results show that the movement of individuals in the group would show the directional collective movement to a certain extent during the migration of L. migratoria tibetnsis in different natural environments such as sandy beach, grassland and farmland. The average speed of movement of migratory locust nymphs was 0.1256 m/s, and the movement direction of individual nymphs within interaction radius 0.2 m tended to be aligned. The normalized alignments of migrating movement were 0.8502 in sandy beach, 0.7870 in farmland and 0.6987 in grassland, which showed that migratory locust swarms was highly aligned in collective motion. Next, as the density of nymphs in the group increased up to the critical density 12-15 locusts/m², a transition took place from the disordered movement of individuals within the group to highly aligned collective motions. Due to the reduction of random movement, the migration distance of orderly migrating individuals could be significantly increase to about 2.5 km per day, meanwhile that of disorder movement individuals was only 70-80 m. Therefore, the orderly migrating nymphs improved the probability of achievement of food and other useful resources. When individuals were far away from food, those who moved disorderly could hardly find food. Finally, although no experienced individuals were found in outdoor locust swarm, our model revealed that only a very small proportion (about 3%-5%) of the informed individuals could guide the marching group of locust successfully.