A method for wiring differential signal lines and a PCB are disclosed. The wiring method includes: providing a rectangle-shaped glass fiber fabric formed of glass fibers which are woven and interlaced with each other and an adhesive filled therebetween; determining a wiring direction and obtaining a glass fiber bundle number of the glass fiber fabric in the wiring direction; equally dividing the glass fiber fabric into glass fiber units, and obtaining a width of each glass fiber unit according to a size of the glass fiber fabric in a direction perpendicular to the wiring direction and the number of the glass fiber units; determining a line distance and line widths of the differential signal lines; and according to the line distance and the line widths, forming the differential signal lines on a metal layer along the wiring direction to make the differential signal lines meet predetermined requirements.