Abstract
In this paper, the blade solidity of the tidal current turbine was investigated. Based on the blade element momentum theory, different design flow velocities were selected to design two blade types with different solidities. The geometric parameters of the blade were calculated using MATLAB programming, and the performance of two blades was compared in terms of the start-up flow rate, power generation and thrust by test experiment, which showed that the blade with higher solidity has better start-up performance and higher energy capture efficiency at low flow rates. The performance is better than that of the blade with low solidity, but due to the high solidity, the thrust is also high, which should be taken into account when installing the turbine.