The invention discloses a device and method for detecting an elastic arm. The detection device comprises a base, a linear transmission mechanism, a mounting board, a laser, an angle adjusting mechanism, a charge coupling element, a lens and a detection frame body. The laser and the charge coupling element are used for conducting three-dimensional reconstruction on the elastic arm, the posture characteristics of the elastic arm are detected, efficiency is high, stability is good, and the evaluation repeatability and reproducibility value is lowered.