Addressing the increasingly pronounced near-field effects arising from the development of ultra-large antenna arrays in 6G communications， this paper investigates a covert communication system employing multi-input single-output non-orthogonal multiple access （MISO-NOMA） assisted by a pinching antenna system （PASS）. This research aims to overcome the limitations of conventional flexible antennas in complex wireless environments， specifically addressing deficiencies in signal coverage capability and deployment flexibility. By innovatively deploying positionally adjustable pinching antennas （PAs） on dielectric waveguides， the system effectively harnesses the beam-focusing properties of near-field spherical wave models. An efficient alternating optimization （AO） algorithm is proposed for the joint optimization of transmit power allocation， beamforming vectors and PA positioning. This is achieved by deriving a closed-form power solution， introducing penalty terms to address the rank-one constraint of beamforming， and employing a particle swarm optimization algorithm to locate the optimal PA position. Numerical simulations demonstrate that the proposed scheme significantly enhances system performance in the 28 GHz millimeter-wave band， overcoming the 45 bit/（Hz·s） bottleneck for covert communication rates. Compared with conventional schemes， it achieves a prominent performance improvement， validating the effectiveness and superiority of PASS technology in near-field covert communication.