An inter-relay interference suppression method is proposed at the relay based on the Autocorrelation Matching (AM) theory in the two-path relay cooperative system. The new approach takes three steps at the relay. Firstly, the new method is used to remove the inter-relay interference. Unlike the Partial Interference Cancellation (PIC) and Full Interference Cancellation (FIC) scheme, it is insensitive to the time synchronization between the two relays. Secondly, the signal will pass through a FIR pre-filter to satisfy the autocorrelation diversity condition. The pre-filters of the two relays are identical. Finally, the signal will be Amplified and Forwarded (AF) to the destination. At the destination, the received signal will firstly pass through a reversal filter caused by the relay nodes, then, it will be equalized, demodulated and decoded like the conventional systems. Compared to the PIC and FIC methods, the proposed approach alleviates the burden on the destination and its performance is not so dependent on the assumption that the destination knows the perfect channel state information for every link, moreover, it has good performance and is also robust.