This paper introduces the method of network signal routing in printed circuit board (PCB) for Cat 6. The bandwidth in Cat 6 reaches 250 MHz, which is 1.5 times higher than Cat 5, so the problem of crosstalk is more serious. This design utilize interdigital capacitors which are widely used in microwave and radiofrequency field to successfully solve the problem of crosstalk, and this paper proposes a new method of designing interdigital capacitors in PCBs. Meanwhile, solid capacitors are not used in the design that it can reduce the cost of PCB effectively. Finally, the design is simulated by 3D highfrequency electromagnetic simulation software CST, which improves the efficiency and precision of the design.