A Hash function construction method based on spatiotemporal chaos is proposed. We take the rumor after linearly transformed as a group of initial values and utilize the one-way coupled map lattice of spatiotemporal chaos to iterate the grou p of initial values concurrently.Then in spatiotemporal chaos convergence the pr oper items of the chaos convergence produced in the last space are linearly tran sformed into Hash value of 128 bits.The result obtained shows that the Hash func tion based on spatiotemporal chaos have advantages of irreversibility,weak colli sion and sensitivity to initial values.The method has a stronger secret performa nce than the Hash function based on low-dimensional chaos maps, and it is simple to be realized.