Abstract Microdistance sensor, which can accurately detect the microdistance change, possesses significant applications in the cutting‐edge technologies including biomedicine, energy storage, and info‐communications. However, the high cost, complicated operation, and stringent testing requirements of the existing microdistance sensors limit their widespread application in the frontier fields, especially for the intelligent wearable electronics. Herein, a novel mechanism to detect microdistance change is developed, in which the external microdistance brings a change in the thickness of conductive textile and further converts into a distinguishable electrical signal. The polyester/polypyrrole (PET/PPy) conductive textile is fabricated via in situ solventless polymerization, and the derived microdistance sensor exhibits an ultrahigh sensitivity of 179 m −1 within the detection region of 10–480 µm, a high resolution up to 5 µm, and good stability. The excellent sensing performance can be attributed to the high elasticity, deformation‐recovery property, and 3D network structures of the PET/PPy conductive textile. Furthermore, the wearable sensor is applied to detect the microdistance changes in human and robot activities, providing an efficient and low‐cost solution for microdistance detection in intelligent medical, health monitoring system, and biomimetic robot.