A preset three-stage adjustable downhole choke with choking and pressure measurement functions includes an intake assembly for natural gas filtration, an electrically-controlled telescopic assembly for positioning and clamping the downhole choke with a prefabricated seating nipple, and a three-stage choking assembly for natural gas choking and depressurization. The intake assembly, the electrically-controlled telescopic assembly, and the three-stage choking assembly are sequentially communicated from bottom to top. A first-stage control choke, a second-stage adjustable control choke, and a third-stage control choke are sequentially provided in a gas passage of the three-stage choking assembly from bottom to top. The preset three-stage adjustable downhole choke features convenient installation and removal, three-stage choking and depressurization, and an adjustable orifice diameter of a control choke, and can achieve different choking and depressurization effects.