Stack register plays an important role in reducing memory access at call sites in procedures. But stack registers are not cost free, they have very high cost when overflow happens. In order to solve this problem, this paper proposes an effective algorithm to manage excessive usage of stack registers in self recursive functions, do modification to traditional simplification, and find a optimization method to alleviate register pressure. This algorithm is implemented in ORC2 compiler. Experiments show that this algorithm is very useful in performance improvement of programs having self-recursive function with high execution frequency and great register pressure.