The precision forming technology developed rapidly during passing two decades, however technologies of precision plastic forming the parts with deeper hole are far behind developed countries. The warm backward extrusion-ironing forming technology was presented for precision forming of non-circular hole joint in this paper. The forming process and parameter variable trend were simulated by finite element method, which the software MSC.Marc was applied. The forming die was designed and the forming experiment was finished. The products were deserved with good quality and performance. The feasibility of the forming technology is proved by experimental results and numerical simulation.