The present invention relates to a multi-thread parallelism based integrity measurement hash algorithm optimization method. The optimization method specifically comprises: 1, dividing an integrity measurement hash algorithm into a Read thread and an Update thread, and initializing a counting signal for inter-thread synchronization; 2, storing, by the Read thread, to-be-measured data that is partitioned uniformly into a buffer area array in a data prefetching manner, and performing, by the Update thread, sequential operation processing on the data written into the buffer area array; and 3, when the Read thread writes data into a buffer area, continuously accumulating preset counting signals, and when the buffer area is full, stopping writing and waiting for an operation of the Read thread, and further, sequentially processing, by the Update thread, the data written into the buffer area until the buffer area is empty, and waiting for the Read thread, and implementing synchronization on the Read thread and the Update thread according to a relationship between the counting signals. By using the optimization method of the present invention, measurement time is reduced and measurement efficiency is improved.