The invention discloses a method for testing the interfacial strength of textile fibers, and belongs to the technical field of textile fabrics. Fibers are packaged in an upper sealing colloid, a plurality of lower sealing colloids matched with the fibers in number are arranged, the plurality of lower sealing colloids are limited in a limiting clamp, the other ends of the fibers are packaged in the lower sealing colloids, and resin pouring packaging is utilized, so that the fibers are convenient to fix, and a good fixing effect is achieved. During testing, the multiple fibers move upwards along with the upper sealing colloid, after a trigger mechanism between the lower sealing colloids and the limiting clamp is triggered, displacement sensors are started with the trigger as a signal, the multiple displacement sensors conduct independent displacement measurement on the multiple fibers, and when any fiber is broken in the pulling process, the lower sealing colloid located at the lower end of the fiber falls down, at the moment, a lower contact piece and an upper contact piece at the position are disconnected, and the displacement sensor corresponding to the position stops displacement counting and stores the displacement amount at the moment. The maximum tensile displacement amount can be recorded when a pull test is carried out on multiple fibers synchronously and tested, and the testing efficiency is high.