Abstract: The compiling schema and optimization strategies of a CLP system are discussed in this paper. The system is a multi-domain CLP system, based on interval arithmetic and constraint propagation as the unified constraint solving method for the discrete domain and real domain. This compiler can solve non-linear constraints based on an extended WAM instruction set. So far we have not found in literature any similar CLP system combining the three features features:multi-domain, non-linear constraints and compilation.