Use-after-free (UAF) vulnerability is a common concurrency defect in multi-threaded programs. Predictive UAF vulnerability detection methods have attracted much attention for their balance of false positives and misses. However, existing predictive UAF detection methods are not optimized for the target to be detected, which leads to unacceptable detection efficiency when the program is large or has complex behavior. To address the issue, proposes a target-oriented method to detect UAF vulnerabilities in multi-threaded programs. Firstly, the Petri net model of the program is mined from the program traces. Then, for each potential memory Free and Use operation pair that could constitute a UAF vulnerability. To add behavioural control structures that maintains causal constrains and data consistency between operations to the Petri net model of the program, with the target of triggering the vulnerability. On this basis, a UAF vulnerability detection method based on Petri net reverse unfolding is designed. This method verifies the authenticity of only one potential UAF vulnerability at a time, thus ensuring the efficiency of detection. This method verifies the validity of one potential UAF vulnerability at a time, thus ensuring the efficiency of detection. At the same time, in order to reduce the number of potential UAF vulnerabilities to be detected, a new vector clock is proposed in this paper to automatically identify the causal relationship between Free and Use operations, and to filter the potential UAF vulnerabilities accordingly. The proposed method is experimentally evaluated with several program examples. The experimental results show that the proposed method improves the efficiency and accuracy of detection compared to the mainstream methods.