<p>The article investigated the loosening mechanism of threaded connections and evaluated the anti-loosening performance of a threaded connection structure called threaded rod connection. First, a comparative analysis of loosening behavior was conducted on three threaded connections: conventional bolted connection, same-direction threaded rod connection, and opposite-direction threaded rod connection. Subsequently, finite element models of the three threaded connections were developed and the correctness of the model was verified by comparing with theoretical results. Thereafter, the research assessed the effects of transverse vibration amplitude, initial clamping force, and friction coefficients on the loosening behavior of the three threaded connections quantitatively through systematic finite element analysis. In the end, a transverse vibration testing machine was developed, and the transverse vibration test was conducted to further validate the rationality of the loosening analysis. Results indicate that compared with the nut, the contact between the bolt bearing surface and the plate is more unstable under transverse vibration, and the bolt is more prone to rotate in the loosening direction than the nut. The loosening rate of the opposite-direction threaded rod connection is approximately 4 times that of the bolted connection, and the main reason for its high susceptibility to loosening lies in the threaded rod tendency to rotate in the loosening direction. In contrast, same-direction threaded rod connection demonstrate outstanding anti-loosening performance when subjected to diverse complex working conditions. The clamping force loss of the same-direction threaded rod connection is less than 10% of the initial clamping force.</p>