Many actual systems can be represented as discontinuous nonlinear block oriented models. Switch functions are often applied to describe discontinuous parts. However, this formulation seems only suitable for recursive parameter estimation but not appropriate for adaptive controller design. Therefore, a self tuning control scheme is proposed for a class of Hammerstein model with discontinuous nonlinearity, which is parameterized by a number of piecewise-linear functions. The adaptive control law is derived from the inversion of the piecewise-linear function. Theoretical analysis proves the stability of the closed-loop system. The simulation results show the effectiveness of the proposed algorithm.