This paper presents a novel microrocket with an eccentric nanoengine, consisting of polymer SU-8, magnetic nickel (Ni), and catalytic platinum (Pt). A circularly steerable propulsion mechanism for the microrocket with the eccentric nanoengine is proposed. For the first time tiny Pt–Ni–SU-8 microrockets are fabricated via a layer-by-layer deposition method based on nano-electro-mechanical systems (NEMS) technology. The steerable propulsion of the fabricated microrockets is characterized in hydrogen peroxide (H₂O₂) solution of different concentrations, revealing that oxygen (O₂) bubbles are generated and detached from the eccentric nanoengines catalyzing H₂O₂ decomposition. The results show the speed of microrockets increases with the increment of H₂O₂ concentration. In addition, microrockets propelled by the detachment of O₂ bubbles can autonomously realize the circularly steerable propulsion in H₂O₂ solution.