The work aims to study the effects of Mn-C composites on the properties of Poly-3-hydroxybutyrate- co-3-hydroxyhexanoate (PHBH) packaging film, so as to prolong the shelf life of fruits and vegetables. Mn-C/PHBH active packaging films were prepared via solution casting method. The microscopic morphology, crystallinity, thermal stability, mechanical properties, barrier properties and fresh-keeping effect of Mn-C/PHBH were studied through SEM, DSC, Universal Capability Testing Machine, Moisture Permeability, Oxygen Permeability and Carbon Dioxide Permeability Detection, Gas Analyzer and Fresh-keeping Evaluation. The tensile strength of Mn-C/PHBH with the 5% Mn-C composites reached the maximum value of 24.38 MPa. Moreover, the prepared active packaging film had selective permeability, which was conducive to forming a low oxygen and high carbon dioxide packaging atmosphere. The shelf life of fruits and vegetables could be prolonged when the active packaging film with ethylene removal ability was used in the storage of fruits and vegetables. The optimum doping ratio parameters of Mn-C composites can be obtained when the comprehensive properties of Mn-C/PHBH active packaging film are the best.