The article presents a method for forming military transport convoys under martial law, incorporating civilian vehicles to meet increased logistical demands. The proposed approach uses a composite criterion to select vehicles, aiming to maximise convoy reliability and readiness while minimising brand and numerical diversity. A multi-criteria optimisation process evaluates vehicles based on tactical and technical parameters, including speed, payload, passenger capacity, fuel consumption, and maintenance range. The method ensures convoys meet operational constraints such as cargo weight and volume, personnel capacity, fuel type limits, and technical readiness. An algorithm and corresponding software automate the vehicle selection process. The method was tested on various datasets, demonstrating its effectiveness in applying four main criteria under specific constraints, such as travel time, readiness coefficients, and transport capacities. The results support optimal convoy composition through a substantiated mathematical model and software implementation tailored for efficient military logistics planning.