In order to solve the problem of signal integrity displayed in the design high-speeding digital circuit,a delay distribution method of high-speeding digital circuit was discussed in this paper.The maximum matching length of termination trace based on the transportation theory was set up,which was helpful to decrease the termination reflection in PCB designing.The crosstalk model and the termination means based on the electronics theory were also discussed, which was used to eliminate the crosstalk.Analyzing the composite disturbance of noise current I_n and transient load current I_L,some restrain methods were taken, which ensured the delay signal integrity.