Resistance-type flexible strain sensors have emerged as a focal point in research due to their straightforward design, expansive measurement capabilities, ease of miniaturization, and seamless integration. The advent of 3D printing technology has revolutionized the fabrication of flexible sensors, enabling the rapid and precise customization of conductive layers at ambient temperatures. This study develops a novel VO \(_2\) -doped multi-walled carbon nanotube (MWCNTs) based flexible strain sensor through systematic optimization of 3D printing parameters. By synergistically combining MWCNTs—a highly conductive and cost-effective material—with vanadium dioxide (VO \(_2\) ) and silicone rubber (Ecoflex), we achieved enhanced sensing performance and multi-functionality. Through systematic parameter optimization, we crafted a high-performance patterned flexible strain sensor that demonstrated superior strain capacity, robust conductivity, and remarkable cycling stability. We further developed an integrated human-machine interaction system by incorporating these sensors with signal conditioning circuits, an STM32 microcontroller, and Bluetooth communication. The system successfully demonstrated real-time gesture recognition, temperature alerting near the VO \(_2\) phase transition point, and environmental temperature monitoring through an additional thermistor. The flexible strain sensor developed in this study holds immense promise and versatile applicability, particularly in the realms of wearable smart devices, soft robotics, and the intricate arenas of industrial production and daily life.