Abstract: In order to study the improvement of highland barley fiber on the mechanical properties of ecological concrete,NaOH,NaOH+H₂O₂,or glacial acetic acid + NaClO₂ are used to modify the surface of highland barley fibers. The optimum modification method is sought through the orthogonal test. Meanwhile,with the assistance of modern material testing methods like XRD,FTIR,SEM etc.,modification effects are evaluated from different perspectives. The highland barley fiber before and after modification is then mixed into ecological concrete,measuring its compressive,splitting tensile and flexural strength respectively to analyze modification effect and its influence on the mechanical properties of the ecological concrete. The results show that the pretreatment of highland barley fiber with 6%NaOH+10%H₂O₂ solution at 40～50 ℃ has a superior surface modification effect. In addition,the incorporation of fibers has decreased the pore contents inside the ecological concrete. The compressive strength of fiber ecological concrete is lower than that of ordinary ecological concrete,while its tensile and bending resistance are significantly enhanced. Compared to unmodified fiber concrete,the 28 d compressive,flexural,and splitting tensile strengths of modified fiber concrete has increased by 4.3%,16.5% and 20.3% respectively. Hence,cellulose in highland barley fiber is effectively purified,which greatly improves the integrity and toughness of the ecological concrete structure.