To explore the effects of different wall conditions on fish swimming ability, crucian carp, a typical fish with carangiform swimming mode, was selected for 1:1 biomimetic modeling. Computational fluid dynamics (CFD) combined with dynamic meshing technology was employed for 2D unsteady simulations of autonomous propulsion under various wall conditions. The study analyzed the impact of kinematic parameters like frequency (f) and amplitude (A) on swimming performance across different wall scenarios. Results showed that at low frequency (f=1.7 Hz) and small amplitude (A=0.04 L), a single - sided wall increased the fish's acceleration during the start - up phase and its cruising speed. When frequency rose from 1.7 Hz to 2.5 Hz at constant amplitude, acceleration under single - and double - sided walls rose by 52.7% and 75.9%, respectively. Similarly, when amplitude increased from 0.06 L to 0.07 L at constant frequency, acceleration under single - and double - sided walls rose by 32.4% and 33.3%, respectively. In low - frequency and small - amplitude conditions, a single - sided wall significantly enhanced propulsion. Within the low - frequency and high - amplitude range, increasing frequency and amplitude can significantly improve swimming speed. This study offers a useful reference for fish behavior research.