Abstract: The security of traditional wireless communication mainly implemented in the upperlayers, which cannot achieve the protection of the modulation type and physical layer information. However, wireless physical layer security exploits the physical characteristics of the wireless channel to achieve secure communications. An efficient physical layer encryption algorithm was proposed in this paper employing Latin rectangle based on 3D Lorenz map aiming to scramble the constellation map. The algorithm makes the most of the properties of modulation in complex field, which attains a lager secretkey space than Boolean algebra field. We studied the security of the proposed algorithm in terms of theoretical analysis, randomness tests using NIST(National Institute of Standards and Technology), key space, key sensitivity and the recognition of modulation type. Compared to the existing physical layer cryptosystems, the proposed method achieves higher security with less calculation and the security of the proposed method is verified through different tests. Both theoretical analysis and simulation results show that on the premise of ensuring the reliability, the proposed method can enhance the system security effectively.