In this paper, based on the Lyapunov stability theory, the impulsive synchronization asymptotic stability condition for different hyperchaotic systems with time delay and parameter uncertainty is first presented by using the linear feedback of state variable error between the slave system and the master system as the impulsive control signal. After the synchronization, a digital communication system with time delay is provided to achieve secure communication. This scheme is of high security and robustness. Moreover, computer simulations show that in the communication system, the synchronization of the systems could be achieved quickly, and by using chaotic cipher sequence to encrypt the digital signal, the useful information signal can be recovered effectively from the receiver.