This paper proposed a secure beamforming design and resource allocation optimization scheme for intelligent reflecting surface (IRS) assisted simultaneous wireless information and power transfer (SWIPT) systems. This scheme considered the maximum transmission power, minimum received energy, IRS phase shift, and PS coefficient constraints of the base station (BS), and a non convex optimization problem was established to jointly optimize the beamforming vector, artificial noise vector, IRS phase shift matrix, and PS coefficient of BS’s transmission with the goal of maximizing secrecy rate. This scheme adopted the alternating optimization algorithm to decouple the optimization variables, and used the successive convex approximation algorithm and alternating optimization algorithm to solve non convex subproblems. The simulation results show that compared with traditional schemes, the proposed algorithm and scheme can further ensure the security performance of the system while optimizing resource allocation.