Abstract: With the rapid development of flexible electronics and human-machine interaction technologies, flexible piezoresistive sensing systems featuring high conformability, low latency, and high sensitivity have attracted increasing attention in wearable motion monitoring and intelligent control applications. In this work, a flexible piezoresistive finger motion detection and control system is designed and implemented to achieve synchronous motion control between the human hand and a robotic hand. The system employs highly flexible and stretchable piezoresistive sensing units attached to finger joints, enabling real-time detection of both single-finger and multi-finger motions by sensing resistance variations induced by finger bending. From a system implementation perspective, a multi-channel signal acquisition and embedded processing platform is developed based on an STM32 microcontroller. A rule-based multi-state mapping method is further adopted to realize real-time mapping between detected finger motions and robotic hand driving commands, thereby enabling low-latency and stable human–machine motion synchronization. Experimental results demonstrate that the proposed system exhibits good response consistency and repeatability over a finger bending range of 0–90°, with inter-channel crosstalk below 1%. In multi-finger gesture recognition experiments, the system achieves an average recognition accuracy of 96.8% for nine representative gestures. In addition, the median response time for single-finger motion is 80ms, satisfying the real-time requirements of low-latency human–machine interactive control.