Provided are an LED driving circuit and a tube lamp. A grounding terminal of a rectifying unit of the LED driving circuit is electrically connected to a first ground wire, and an input terminal of an impedance detection and protection unit is electrically connected to a second input terminal of a first filtering unit. The grounding terminal is electrically connected to the first ground wire. The impedance detection and protection unit is configured to detect an impedance between the second input terminal of the first filtering unit and the first ground wire, so as to control the second input terminal of the first filtering unit to connect to or disconnect from the first ground wire according to a magnitude of the detected impedance.