Research focuses on the physical layer security (PLS) of mobile antenna arrays (MA) in near-field (NF) scenarios. A base station (BS) with an MA array serves a user with a single antenna, while multiple eavesdroppers with single antennas listen in. In order to reduce the risk of eavesdropping, a near-field MA-assisted secure transmission framework is proposed. The aim of this framework is to maximize achievable secrecy rates by jointly optimizing the base station’s beamforming vectors and mobile antenna positions. For this problem, high-quality suboptimal solutions are obtained through the Alternating Optimization (AO) algorithm and the Projected Gradient Ascent (PGA) method. Simulation results demonstrate that, compared to secure communication assisted by far-field MA and secure communication assisted by fixed antennas (FPA) in the near-field, this near-field MA secure transmission framework significantly enhances the security of information transmission. Specifically, when the base station transmission power is 10 W, the secure transmission rate increases by approximately 15 \(\%\) and 18 \(\%\) , respectively.