Composites damage test is a difficult problem in helicopter groud maintenance at present.According to rules of helicopter periodic inspection and repair,thermography testing was applied to detect low energy impact damage in rotor blade and composites skin in this paper.By heat stimulating outside,interior different heat exchange course makes different temperature distributing in corresponding surface,so infrared images can show clearly structure character and damage inside composites.This technique is quick and visual,it can provide intuitionistic damage image and referenced data for making repair or replacing plan,so it has wide applied prospect in daily and emergency maintenance of helicopter in service.