The stability of dam construction by tailings accumulation is closely related to the ultimate bearing capacity of geotextile used in dam construction. The fine tailings of Dayu Shilei Tungsten Mine in Ganzhou are used as the filling material. Through the uniaxial compressive strength test of the filling geotextile filled with fine tailings under different consolidation time and different filling degree, the variation law of the ultimate compressive strength of the geotextile and the failure mode of the geotextile and the strength reinforcement mechanism of the bag body are analyzed. The results show that when the geotextile reaches the ultimate compressive strength, the vertical strain is between 20% and 30%; The ultimate compressive strength of geotextile decreases with the increase of tailings filling degree (filling height), and increases with the increase of consolidation time. Under uniaxial compression, the failure position of the geotextile mainly occurs at the bottom of the intermediate geotextile, and the lower the filling degree, the greater the failure range is; The theoretical calculation value of the modified formula of ultimate compressive strength considering the influence of filling degree is compared with the experimental value of ultimate compressive strength, and the error between them is less than 4%. The conclusion can provide reference for similar fine-grained tailings geotextile dam construction.