A cantilever micro-thrust measurement system is proposed in this paper， which is used to measure the generated dynamic thrust of a flexible biometric fin actuated by macro fiber composites （MFC）. Based on the bending and torsion deflection theory of cantilever， the design parameters of the cantilever are obtained. The experimental calibration result of the bending rigidity matches well with the desired index. The underwater experiments show that the proposed fin achieves its maximum peak-to-peak oscillation magnitude of 5.08 mm and velocity of 104.3 mm/s in the steady state， with the excitation frequencies of 7 and 8 Hz， respectively. The generated dynamic thrust of the fin in the cases of the maximum oscillation displacement and velocity are experimentally obtained using the proposed measurement system. It can be seen that the generated thrust is fluctuated with two peaks within one oscillation circle， and both the thrust-producing and drag-producing pattern are observed in the oscillating periods. In the case of the maximum oscillation velocity， variations of the measured thrust shows that the MFC-actuated flexible fin is indicative of the thrust-producing pattern in 62.9% of an oscillation circle in the steady state， and the generated maximum instantaneous thrust， drag and mean thrust are 6.24， 2.50 and 1.90 mN， while the generated mean thrust is only 0.26 mN in the case of the maximum oscillation displacement. Accordingly， the feasibilities of the proposed MFC-actuated biomimetic fin and micro-thrust system are demonstrated.