Abstract： In this paper, a Top-k query algorithm based on node pruning rules was proposed. The concept of a set dominate region and pruning rules were defineded. As the position of users change in the dynamic set dominate region, the nodes of wireless sensor networks were pruned which conformed to pruning rules. The statistical sampling theory was used to design an approximate Top-k query algorithm based on spatial keyword. Experiments on two real datasets were made to validate the effect of the algorithm. The results show that the algorithm meets the needs of users in sensor network environment and it has an advantage of low energy consumption compared to the incremental border distance (IBD) algorithm and query algorithm of spatial keyword based upgraded MWVoronoi region (MSK-uvr).