Inspired by the spider's slit organ embedded in the leg joint exoskeleton and its ultrasensitive stress perception, we propose to fix the conflict between the stress concentration requirement for bright mechanoluminescence (ML) and the stress dispersion effect of soft material via integrating slit microstructures into flexible films. The designed slits focus weak stresses onto the corner to achieve high sensitivity, leading to 10−30 times ML intensity improvement at weak strain (<10% stretch) application. Slit morphology and various patterns were well investigated to address the stress distribution regularity. The slit-based ML film offers a facile light-luminescent artificial skin for visualizable stress presentations or detections without electricity power source. It is a practical endeavor of photonic skin for visible vocalization and a significant contribution to dysaudia auxiliary or luminescence augmented expressions for human social interactions, similar to jellyfish or squids.