A novel 3D piezoelectric fabric (3DPF) sensor is developed using ultrahigh strength PVDF piezoelectric nanoyarns and advanced 3D textile technology. The 3DPF exhibits exceptional tensile strength (46.0 MPa) and superior breathability, enabling efficient sweat transport from the inner layer near the skin to the outer layer in 4 seconds. This design ensures a comfortable and dry environment for the user, while also enhancing the piezoelectric properties of the sensor due to the presence of sweat. The 3DPF is comparable in durability and comfort to commercial cotton T-shirts. The sensor is composed of different yarns with varying hygroscopic properties, including PVDF nanoyarns, silver-nylon yarns, Coolmax yarns, viscose yarns, and polyester yarns. The 3DPF demonstrates high sensitivity and fast response time, with sensitivity increasing from 0.41 V kPa⁻¹ in the dry state to 3.95 V kPa⁻¹ in the wet state. The sensor is also suitable for long-term wear as a self-powered switch, capable of triggering alarm signals or location information via Wi-Fi or a 4G module. The 3DPF has potential applications in healthcare, such as a bedsheet for call systems and a belt for missing children's alarm systems. The sensor's unique structure allows for unidirectional water transport, preventing bedsores and maintaining skin dryness. The 3DPF is also washable and maintains its performance after multiple washing cycles. The study highlights the balance between comfort and sensing properties, making the 3DPF a promising candidate for intelligent wearable products.A novel 3D piezoelectric fabric (3DPF) sensor is developed using ultrahigh strength PVDF piezoelectric nanoyarns and advanced 3D textile technology. The 3DPF exhibits exceptional tensile strength (46.0 MPa) and superior breathability, enabling efficient sweat transport from the inner layer near the skin to the outer layer in 4 seconds. This design ensures a comfortable and dry environment for the user, while also enhancing the piezoelectric properties of the sensor due to the presence of sweat. The 3DPF is comparable in durability and comfort to commercial cotton T-shirts. The sensor is composed of different yarns with varying hygroscopic properties, including PVDF nanoyarns, silver-nylon yarns, Coolmax yarns, viscose yarns, and polyester yarns. The 3DPF demonstrates high sensitivity and fast response time, with sensitivity increasing from 0.41 V kPa⁻¹ in the dry state to 3.95 V kPa⁻¹ in the wet state. The sensor is also suitable for long-term wear as a self-powered switch, capable of triggering alarm signals or location information via Wi-Fi or a 4G module. The 3DPF has potential applications in healthcare, such as a bedsheet for call systems and a belt for missing children's alarm systems. The sensor's unique structure allows for unidirectional water transport, preventing bedsores and maintaining skin dryness. The 3DPF is also washable and maintains its performance after multiple washing cycles. The study highlights the balance between comfort and sensing properties, making the 3DPF a promising candidate for intelligent wearable products.