The invention relates to a probe device and an operation method thereof. The probe device comprises a probe, a processor, a gravity sensor and a distance sensor. The probe is used for scanning an object. The processor stores a first direction and a first distance in advance. The gravity sensor and the distance sensor are electrically connected with the processor. The gravity sensor is used for detecting the placing direction of the probe and returning the disposition direction to the processor. The distance sensor is used for detecting a detection distance between the probe and the object and returning the detection distance to the processor. When the processor determines that the placing direction is the first direction and the detection distance is smaller than or equal to the first distance, the probe device enters a working mode. When the processor determines that the placing direction is the first direction and the detection distance is larger than the first distance, the probe device enters a standby mode. When the processor determines that the placing direction is not the first direction, the probe device enters a sleep mode. The probe device performs detection via corresponding parameters and selects to enter different modes, thereby achieving the object of power saving.