A flexible printed circuit board for connecting external modules, includes a high-frequency signal wiring board and a low-frequency signal wiring board. Side edges of the high-frequency signal wiring board and the low-frequency signal wiring board are connected to each other. The low-frequency signal wiring board is folded toward the high-frequency signal wiring board to form a stacked double-layer board structure. Each of two ends of the high-frequency signal wiring board extends to form a connecting board for connecting the external module. A flexible printed circuit board combination includes two flexible printed circuit boards.