In this paper the problem of global or semi-global non-regular static state feedback linearization of affine nonlinear systems is considered. Based on a normal form and a non-regular linearization technique developed recently by authors, this paper first provides a detailed algorithm for the linearization procedure. Then it also presents an easily verifiable condition to estimate the linearizable region, which solves the semi-global linearization problem. An example is included to describe the method and verify the efficiency of the estimation.