In intelligent transportation systems, vehicular platooning is crucial for enhancing traffic flow and driving safety. However, the stability and safety of existing platoons rely on vehicle reliability and trustworthiness. Traditional vehicle reputation assessment mechanisms employ periodic evaluations, collecting feedback only at the end of each cycle. This mechanism fails to promptly reflect a vehicle’s behavior throughout the entire cycle, potentially leading to delayed identification of uncooperative or malicious vehicles. This paper proposes a dynamic reputation assessment mechanism based on real-time feedback. It collects and calculates feedback information from all vehicles in real time, comprehensively and accurately reflecting each vehicle’s performance throughout the entire assessment cycle, thereby enabling more precise evaluation of vehicle reputation. Furthermore, ECC and Paillier encryption techniques are employed to ensure efficient reputation updates while protecting vehicle identity privacy and maintaining the confidentiality of feedback scores. By continuously monitoring vehicle behavior and updating reputation scores based on feedback, this scheme effectively identifies reliable vehicles for vehicular platoon participation while detecting and handling non-cooperative or malicious vehicles. Experimental results demonstrate that our scheme outperforms the existing scheme in computational and communication efficiency while effectively safeguarding vehicle privacy and feedback scores.