To improve the technique of optimizing reversible logic circuit and reduce the cost of reversible logic circuit, the template technology is analyzed, finding that Maslov's templates are incomplete in that the control lines are incomplete. By introducing the library of template control lines concept, templates are reconstructed and named semi-template. The semi-templates do not realize the identity function, but more valid templates can be produced dynamically using template producing rule. And based on this method, an algorithm is provided to optimize reversible logic circuit. Experimental data show that this method is more efficient and has higher rate of matching success in optimizing reversible logic circuit.