The utility model relates to a colliery gas drainage throttling arrangement, first steel pipe is " protruding " font, the inside annular groove that sets up of one end of second steel pipe, reserve porosely on the pipe wall of first steel pipe and second steel pipe respectively, it has two holes to reserve on the second steel pipe, the orifice plate is cylindrically, inside constant head tank and the through -hole of setting up respectively of orifice plate, reserve porosely on the lateral wall of constant head tank, registrating of the inside constant head tank of the little one end of a steel pipe diameter and orifice plate, the orifice plate is embedded on the annular groove of second steel pipe, the outer terminal surface and the outstanding inner facial features laminating of first steel pipe of the annular groove of second steel pipe, adopt the clamp to carry out fixed connection between first steel pipe and the second steel pipe, the pore pair of reserving on the hole of reserving on the pipe wall of first steel pipe and second steel pipe and the lateral wall of constant head tank should, hole female connection gets the pressure mouth. The utility model discloses simple structure, it is not perishable, the maintenance of being convenient for, convenient location can effectual save time, improves work efficiency.