In this paper, we propose an algorithm which can improve Katz and Rosenschein's plan verification algorithm. First, we represent the plan-like relations with adjacency lists and inverse adjacency lists to replace adjacency matrixes. Then, we present a method to avoid generating useless sub-graphs while generating the compressed set. Last, we compare two plan verification algorithms. We not only prove that our algorithm is correct, but also prove that our algorithm is better than Katz and Rosenschein's algorithm both on time complexity and space complexity.