Vibration is the main reason for earthen sites to deform and collapse. It is necessary to get vibration data for providing basis to further conserving earthen sites. Traditional monitoring methods are not suitable for the earthen sites because it is destructive and unsustainable. We use the technique of wireless sensor network (WSN) to get the vibration data, and delve into how to transmit large amounts of data reliably while ensuring the transmission quality. An algorithm CAPK with probability caching based on the Wisden system of the University of California was proposed in this paper. The analysis of simulation and simulation experiment results prove that the algorithm has better performance, low consumption and high reliability, which makes the foundation of future research work.