The development of intelligent agriculture urgently needs to transcend traditional environmental monitoring to achieve precise and real-time perception of the internal physiological state of plants. Nano-sensors provide unprecedented technological tools for the in situ， non-destructive， and dynamic analysis of plant physiological processes due to its ultra-high sensitivity， excellent specificity， and good biocompatibility with biological systems brought about by nanoscale effects. This article systematically reviewed the principles of design， material systems， and cutting-edge applications of nano-sensors for monitoring plant growth， with a focus on analyzing the mechanisms and efficacy of nano-sensors in the dynamic detection of key physiological signaling molecules including H?O?， Ca2?， phytohormones within plants. The new challenges and emerging solutions presented by the unique properties of nano-sensing data including near-infrared fluorescence imaging and high-frequency electrochemical signals for agricultural Internet of Things （IoT）， data mining， and intelligent modeling were discussed. The full-chain integration pathway from data acquisition and intelligent processing to decision support was elaborated in detail by combining an example of an “Intelligent planting analysis system” that integrates multi-source nano-sensing data. The bottlenecks and development directions of nano-sensors in moving towards large-scale field applications in the future was systematically prospected from four dimensions including material innovation， intelligent anti-interference， system integration， and risk assessment. It will provide a solid theoretical reference for studying the intersection of intelligent agriculture and nanotechnology.