Due to the gradual increasing of spam's harm to the society, the anti-spam technology has been the focus of attention of all sectors. In this paper, we bring forward the Bayesian filter technology based on Anti-Spam Grid, which can realize the cooperation among various servers and comprehensive utilization of grid resources, and ultimately improve the accuracy and efficiency of spam filtering. We analyze the Anti-Spam Grid, design and implement the grid-based Bayesian filter, and experimentally verify the effect of the filtering system.