A speckle measuring instrument based on embedded system for high-precision in-plane displacement measurement is studied and implemented. The ARM chip is used to replace the computer for image processing and calculation in the traditional digital speckle correlation. Laser ranging module and angle sensor are used to realize multiple measurement at different distances. App is used to realize remote control measuring instrument. Video acquisition

image display and in-plane displacement calculation are realized with Open CV and ARM. The humancomputer interaction interface is designed with Qt. The measuring instrument can measure the in-plane displacement within 10 m

the measuring accuracy is higher than 0. 3 mm and the measuring error is less than 3 %.