The present disclosure provides microwave intrusion detecting device with multi-direction and multi-range fence which detects human or vehicle intrusions within altering range by transmitting microwave signals and receiving echo signals. It includes pair of detecting units, a signal unit, a processor, a control interface, an alarm unit, a storage unit, a communication unit, and a power supply unit. The pair of detection units are physically composed back-to-back which can form a long-distance electronic fence. The second detection unit can be separated from a main body to adjust the antenna coverage angle to adapt to environment or obstacles. The signal unit generates the frequency modulated continuous wave signal to the two detecting units respectively. The processor can set thresholds segments to from passing gates in microwave intrusion detecting device and can generate an alarm unit message.