This paper describes the deployment optimization technology and the cross-layer design of a surveillance WSN system applied in relic protection. Facing the typical technical challenges in the application context of relic protection, we firstly propose a deployment technology based on ant colony optimization algorithm (DT-ACO) to overcome the difficulties in communication connectivity and sensing coverage. Meanwhile, DT-ACO minimizes the overall cost of the system as much as possible. Secondly we propose a novel power-aware cross-layer scheme (PACS) to facilitate adjustable system lifetime and surveillance accuracy. The performance analysis shows that we achieve lower device cost, significant extension of the system lifetime and improvement on the data delivery rate compared with the traditional methods.