Research on the mechanical amplification function of natural organisms presents a bio-inspired approach for the future design of strain sensors to be embedded in engineering bodies. By the observation under FTEM, the micromorphology of chafer cuticle is found as follows：insect cuticle is a typical example of a natural composite plate with cross-fiber laminates reinforced，on the surface of which a series of trichopores with diameter of 50~70 μm are distributed in the space of 40~50 μm. This microstructure is characterized as a composite plate with holes with cross-fiber laminates reinforced. The stress amplification factor that helps to improve sensilla’s sensitivity is achieved as 2.424 by finite element method and weighted average method. Furthermore continuous helicoidal fibers around the channel under trichopore are found，which resist stress concentration from every orientation and protect the gland and body wall.