Detection device of micro water in transformer oil and transformer provided with same

The invention provides a detection device of micro water in transformer oil and a transformer provided with the same; the detection device of the micro water in the transformer oil includes a micro water sensor, a data processing unit for receiving a detection signal outputted by the micro water sensor, and a detection head fixedly mounted on the transformer; the detection head is provided with a sensor mounting rod for passing through an internal channel of a detection sampling valve pre-arranged on the transformer and then extending to a transformer circulating oil way for an insulating oil to flow; the micro water sensor is arranged on a rod section, extending to the circulating oil way, of the sensor mounting rod. The micro water sensor directly extends to the circulating oil way on the transformer, the insulating oil in the circulating oil way is directly detected real-timely online through the micro water sensor, an oil pump is not required to be alone arranged for pumping the insulating oil to simulate the insulating oil in the circulating oil way of the transformer, and in the premise of ensuring measurement accuracy, the cost of the whole detection device is effectively reduced.