The invention belongs to the field of electric power equipment, and relates to a main transformer on-load switch dismounting-free rapid sampling apparatus; a hollow iron pipe tail is arranged in an installing hole of the pedestal, and an outer periphery of the hollow iron pipe is sleeved with a copper cover cap, and the lower end of the copper cover cap is arranged in a pedestal installing hole; the tail of the hollow iron pipe is in conical shape, and the side surface of the hollow iron pipe is radially opened with an oil port, and the head of the hollow iron pipe is opened with an oil outlet and an oil extraction nozzle, and the oil outlet and the oil inlet are communicated by a hollow channel of the hollow iron pipe. The apparatus has a simple structure and is used conveniently, and is suitable for 110 KV and 35 KV main transformer in substation.