This paper proposes a method to reduce communication costs by using hash functions in the process of counting the number of subgraphs under edge-local differential privacy. Existing graph statistics computation algorithms based on edge-local differential privacy have high communication costs, making them difficult to apply to large-scale graphs. In this paper, we introduce linear congruence hashing to solve this problem. Using a sampling rate $s$ can reduce the communication cost by $s^2$, but the variance of the published graph statistics increases by $s$. Experimental results show that the $\ell_2$-error for the triangle count is reduced by up to 1000 times compared to the existing state-of-the-art algorithms with the same communication cost.