Current sensor unit and current detection circuit

The embodiment of the invention discloses a current sensor unit and a current detection circuit. The current sensor unit comprises: a rectification module which is used for converting an alternating current into a pulsating direct current; a power supply conversion module which comprises an energy storage element and stores energy for the energy storage element based on the pulsating direct current when working in a charging mode and generates a power supply current; a mode switching module which is bypassed by the power supply conversion module when working in a charging mode, and bypasses the power supply conversion module when working in an energy release mode; a current sensor module which detects the pulsating direct current; a control module which obtains electric energy from the power supply current, determines to work in a charging mode or an energy release mode, and obtains a first detection value provided by the current sensor module; a self-calibration module which is used for generating a preset c