In this study, highland barley powder was modified by the extrusion method and the changes of characters of highland barley powder were investigated. The farinograph parameters of pre-gelatinized powder and the effects of extrusion on the characters of highland barley noodles were also researched. The results showed that porous sponge was formed inside highland barley after modification while macromolecule nutrients were degraded and starch stability was enhanced. Meanwhile, the correlation between the noodle cooking loss rate and degree of starch gelatinization was obtained. Using the pre-gelatinized highland barley powder obtained under the optimized processing condition as material, one kind of highland barley noodle was researched, which contained 60% pre-gelatinized highland barley powder. The cooked weight gain rate and the cooking loss rate of highland barley noodles were 77.0% and 12.0%.