The invention relates to the technical field of improvement of the strength of aircraft or high-speed locomotive structural 
fastener connecting holes and specifically relates to a method for intensifying the strength of an aircraft or high-speed locomotive structural 
fastener connecting hole in an extruding mode, in particular to a 
machining method of a split sleeve. The method comprises the following steps that raw materials are selected according to specification requirements of the required stainless steel split sleeve, wherein the raw materials are hard stainless 
steel plates which are subjected to no heat treatment when leave a factory; and the raw materials are subjected to annealing heat treatment and then subjected to rolling depression and leveled on a roller press according to needs, the thickness is adjusted, and after calculation and blank 
layout are completed, the raw materials are 
cut into bar-shaped to-be-machined raw materials. According to the 
machining method of the split sleeve, heat treatment is adopted for the excessively thicker stainless 
steel plates subjected to no heat treatment, firstly the thickness is adjusted, then 
punching blanking and bending and 
rounding linkage forming reinforcing are performed, and the problem that high-strength stainless steel sheets are difficult to form is solved in the mode that the thickness of the stainless 
steel plates subjected to heat treatment is adjusted firstly, and then 
punching blanking and bending and 
rounding linkage forming reinforcing are performed.