The invention discloses a wireless information and power transfer system maximum safety rate optimization method based on NOMA; the method comprises the following steps: firstly, a wireless information and power transfer system based on the NOMA is provided, the system is provided with a cell base station BS, M information receivers IRs and K energy receivers ERs, wherein the ER obtains energy from a radio frequency signal transmitted by the BS and eavesdrops on the information sent by the BS to the IR; according to the principle of the NOMA technology, the information transmitted by the BS tothe IR transmits a signal through a superposition coding technology, and the expression is as follows: formula; in the formula, am is the signal transmission power distribution coefficient of the mthIR, P is the signal transmission total power of the BS, xm is the confidential information of the mth IR, and sigma 2 is the additive gaussian white noise; and an optimization parameter AM is adjusted according to the method, certain energy can be provided for the ER, and a certain information rate is provided for the IR; and the purpose of providing the maximum safety information rate is provided for the IR in the case of the ER eavesdropping on information.