The anti-cavitation ability of the bionic pressure relief valve is investigated, the void fraction λ is employed to quantitatively analyze the gas-phase volume fraction experimentally. The results show that the void fraction is positively correlated with the gas volume fraction. The higher the void fraction, the higher the cavitation strength. Cavitation length and area with the bionic valve core are decreased significantly because of the non-smooth bionic surface. Compared with the traditional valve with a smooth surface, the maximum cavitation length of the bionic valve is reduced by 31.48%, and the maximum cavitation area is reduced by 22.75%. Furthermore, the cavitation inhibition efficiency is proposed to assess the cavitation suppression behavior of the bionic valve. The maximum cavitation inhibition efficiency varies from 63.25% to 72.66% when the flow velocity is in the extent of 42.13–52.66 L/min. Due to the non-smooth bionic surface, the flow field could be effectively perturbed to generate an anti-vortex, the cavitation suppression performance is significantly improved.