In recent years, with the rapid development of Internet technology, cloud computing services begin to widely spread. Large-scale Internet companies, small and medium enterprises have begun to provide their own cloud computing services. The Chinese Academy of Sciences also provides a cloud computing service platform-CAS "science-cloud". Concerned with the actual needs of the "Science Cloud" project of the Chinese Academy of Sciences, this paper designs and implements a spider-based data monitoring system referencing the function and operation mode of the existing commercial cloud monitoring systems. Compared with the commercial cloud monitoring system, this system supports the monitoring of URL (Boolean) type data, adds the monitoring of numeric types and text types, supports better monitoring of the third party services, and realizes service failure alarm and monitoring data Visualization and monitoring data distributed storage.