A batteryless digital TV receiver has a connector mounted on a body and complying with a specific standard, an RF receiving module, a digital TV processor, an authentication chip and a switching power conversion module. When the batteryless digital TV receiver is connected with a handheld device, the switching power conversion module acquires power outputted from the handheld device through the connector, limits an operating power under a specific current, supplies the operating power to the RF receiving module, the digital TV processor and the authentication chip. After the authentication chip and the handheld device finish an authentication step, the digital TV processor receives digital TV signals from the RF receiving module. The digital TV signals are decoded and transmitted to the handheld device and are displayed on the handheld device.