Magnetic reconnection (MR) in the high-energy-density (HED) regime is comprehensively investigated by particle-in-cell simulations. In the HED regime, the MR process is driven by two colliding magnetized plasma bubbles produced by intense lasers, where there are ambiguities in distinguishing the actual MR consequences from the pure bubble squeezing effects, because both lead to similar behaviors. After discerning these similarities, such as two-fluid effects, plasma heating and jetting, we establish the direct relevance between the actual consequences of MR with the electron dissipation region, magnetic energy conversion and the relaxation of plasma density gradient. With additional discussions of the 3D effects and relativistic features, the results will guide the future HED experiments for MR and other laboratory astrophysics studies.