The invention discloses a coupling-type downhole throttle device. After a fishing neck is sleeved with a positioning ring, the fishing neck and the positioning ring integrally penetrate through a first connecting sleeve, a semi-circular ring and a body; a telescopic claw is arranged at the lower end of the fishing neck, and a lock block is embedded into the body; a release sub and an upper central pipe penetrate through two heads in an upper whole correspondingly and are connected through a first shear pin; an inner pipe is embedded into a first transition sleeve, and a second connecting sleeve penetrates into the integral center of the first transition sleeve and the inner pipe and is fixed through a second shear pin; a lower central pipe penetrates through the inner pipe to be in screwed connection with the upper central pipe; a one-way buckle is arranged in the position, located at the lower end of a tool, of the inner pipe, the telescopic claw is arranged in the position, located at the upper end of the tool, of the inner pipe, and a clamping buckle matched with the one-way buckle of the inner pipe is arranged on the inner wall of a one-way lock ring; the inner pipe is sleeved with rubber cylinders, a third connecting sleeve, the one-way lock ring and a second transition sleeve in sequence; and an air nozzle is placed on a cavity of the second transition sleeve. Fishing is easy, the setting position is flexible, the structure is simple, the cost is low, and operation is convenient.