The invention relates to an 
insulin injection pen which comprises a pen cap, a needle, an injection 
pipe, an injection sleeve 
pipe, a locating fixture block, a screw, a nut 
pipe, a fixing pipe, a rotating pipe and a button, wherein a 
piston is arranged in the injection pipe, and 
insulin is filled in the injection pipe in advance. Partial threads on two sides of the screw are respectively 
cut off along the axial direction so that two sections which are parallel to each other are formed. A pressing head is arranged at the front end of the screw, and the screw is coupled with inner threads of the nut pipe. The injection pen further comprises a rotating 
handle and a rotary spring. The rotating 
handle is arranged at the outer end, namely, the side opposite to the pen cap, of the injection pen, the outer end of the rotating pipe is arranged in the rotating 
handle and is fixed on the rotating handle, the other end of the rotating pipe is connected with the nut pipe in a clamping mode, the locating fixture block is sleeved outside the rotating pipe and is connected with the rotating pipe in the clamping mode; the nut pipe is arranged between the pressing head and the locating fixture block; and the rotary spring is sleeved on the rotating pipe, one end of the rotary spring is fixed on the inner side of the rotating handle, and the other end of the rotary spring is fixed on the locating fixture block. According to the 
insulin injection pen, repeated usage can be achieved through repeated adjustment of the locating fixture block, the rotary spring and a 
clutch spring.