A PCB testing method, a PCB manufacturing method and the PCB are disclosed. The testing method includes the steps of arranging a section of line on each signal layer of the PCB, leading the section of line to the surface layer of the PCB through at least one pair of through holes, testing the test value of the section of line through the at least one pair of through holes and determining whether the line width and line thickness of signal line of each signal layer meet the standards according to the test value and the preset threshold indicating the preset resistance. The section of line has preset resistance, preset width and preset thickness, the preset thickness is identical to the thickness of the signal lines on a same signal layer, and the length of the line is determined according to the preset resistance, preset width, preset thickness, and the electrical resistivity of the line. The test value indicates the tested resistance of the line.