Enclosure is one of the important methods used to restore grassland ecosystems. Locusts and grasshoppers constitute an important component of grassland ecosystems, and their abundance is closely related to changes in their habitat. However, currently, the response in abundance of grassland locusts and grasshoppers within short-term enclosure mode and the underlying ecological mechanisms remains unclear. In this study, a three-year short-term enclosure experiment was conducted on a natural grassland in the Ili Kazakh Autonomous Prefecture of Xinjiang, China. According to the results of this study, the diversity of locusts and grasshoppers increased in each grassland type after short-term enclosure. As altitude increased from the temperate desert steppes to the mountain meadows, vegetation cover presented a “decreasing-increasing” trend, and the number of locusts and grasshoppers per unit quadrat showed a “decreasing-increasing-decreasing” trend. As a result of increased vegetation cover and altitude and decreased latitude, the community structure of locusts and grasshoppers shifted from a decrease in terricoles species such as the Sphingonotus species to an increase in phytophilous species like Omocestus petraeus. In contrast to the results of a study performed in the same area 40 years ago, this survey showed that four species of locusts and grasshoppers including Gomphocerus sibiricus shifted toward higher altitudes, causing changes in the community structure of locusts and grasshoppers at higher altitudes; and that Stauroderus scalaris scalaris replaced Gomphocerus sibiricus and evolved into a high-altitude dominant species; and while Pararcyptera microptera microptera shifted toward low altitudes.