We present a novel design strategy for complex multiband rectifiers, named the &#x201C;Rectifying Network Common Items Extraction (RNCIE)&#x201D;. This approach involves sharing one rectifying network (i.e., the common items) between two or more parallel rectifiers, thereby significantly simplifying the design process. In contrast to the traditional global optimization method for multi-band (e.g., <inline-formula> <tex-math notation="LaTeX">$&gt;$</tex-math> </inline-formula>3 bands) rectifier design, our RNCIE strategy can help realize the modular decomposition of the rectifier, including the rectifying network and impedance matching network (with the help of filter branches), thus leading to a significant reduction in design cost and complexity. Additionally, the unique advantage of the RNCIE contributes to in-depth analysis of the influencing factors on the total efficiency of the rectifier. Consequently, the RF-DC conversion efficiency of an example prototype of the rectifier design can be optimized to 44.6% @ 1.8 GHz, 45.4% @ 2.1 GHz, 41.7% @ 2.6 GHz, 33% @ 3.5 GHz, 30.2% @ 4.9 GHz, and 23% @ 5.8 GHz at an input power level of <inline-formula> <tex-math notation="LaTeX">$-$</tex-math> </inline-formula>10 dBm. Meanwhile, our rectifier with a shared rectifying network can improve the total efficiency when multi-tone signal inputs are used (27% @ <inline-formula> <tex-math notation="LaTeX">$-$</tex-math> </inline-formula>20 dBm, 43% @ <inline-formula> <tex-math notation="LaTeX">$-$</tex-math> </inline-formula>10 dBm for a six-tone signal). The strategy is verified by experimental measurements and paves the way for the efficient and accurate design of multi-band rectifiers of high efficiency.