Use maintance-free extension valve stem design scheme, burried underground at one time, advoid the expensive construction cost and multi-times of tansformation of the valve well and valve replacement, which will bring huge investment, beautification on the road conditions, rolling resistance, advoid covers loss that will cause safety accidents. Stem can be expanded according to the depth of the valve well at will, valve switch display is installed on the top of the valve stem, which can be attached with signal remote transmitting devices and valve mistaken lock closed switch device.