WDM optical interconnection is a feasible method overcoming the problem of electronic bottlenecks for parallel computer system, the transmission properties of fiber make high capacity, low latency, low error rate parallel computer interconnection realistic. This paper discussed one kind of structures for parallel computer WDM optical interconnection, researched key technologies of it,and designed a test system. Analysis and test show that parallel computer system with ultrahigh capacity can be achieved by WDM optical interconnection.