High-performance and reliable wearable devices for healthcare are in high demand for the health monitoring of infants, ensuring that life-threatening events can be addressed promptly. Herein, the continuous monitoring of infant respiration for preventing sudden infant death syndrome (SIDS) is proposed using high-performance flexible piezoresistive sensors (FPS). The thorny challenges associated with FPS, including the signal drift and poor repeatability, are progressively improved via the employment of high-Tg matrix, the strengthening of in situ graft-on conducting polyaniline layer by β-cyclodextrin (β-CD), and the nanostructure interlocking between the piezoresistive layer and electrodes. The sensor presents high linear sensitivity (30.7 kPa-1), outstanding recoverability (low hysteresis up to 1.98% FS), static stability (4.00% signal drift after 24 h at 2.4 kPa) and dynamic stability (1.92% decay of signal intensity after 50,000 cycles). A wireless infant respiration monitoring system is developed. Respiration patterns and the real-time respiration rate are displayed on the phone. Notifications are implemented when abnormal status such as bradypnea and tachypnea is detected.