Aiming at the problems of inconvenience and low efficiency of the traditional method of measuring the height of Printed Circuit Board Assembly (PCBA) components in flexible functional testing, an algorithm based on ERH-Stereo STEREO matching PCBA component height measurement is proposed. PCBA objects are collected by binocular ranging principle to obtain RGB images, and then RAFT-Stereo and ECA+UHRNet innovative ERH-Stereo STEREO stereo matching network structure are used to obtain PCBA high-precision parallax map, and then PCBA depth information and component height are obtained. Experiments show that ERH-Stereo's EPE and D1 indexes on Scene Flow dataset reach 0.43% and 5.1%, and the absolute error of height measurement is less than 1mm, which can meet the requirements of flexible design of PCBA test fixture.