The invention belongs to the technical field of marine new energy, and particularly relates to a floating wave and current combined power generation device. An oscillating float type wave energy powergeneration device and a vertical axis ocean current energy turbine power generation device are reasonably integrated through a tower type combined power generation platform composed of a cylindricalcombined power generation chamber, a circular-truncated-cone-shaped tower and a cage disc type tower body. A direct drive transmission mode is adopted, the problem of excessive energy losses in multilayer transmission is avoided, and the internal space is saved. Through a framed structure of the tower type platform, the contact area between the combined power generation device and water is reduced, and the resistance and vortex induced vibration are greatly reduced. The combined power generation device is axisymmetric as a whole, is simle and compact in structure and high in reliability, the total energy output per unit ocean space is increased, and the combined power generation device has high market application value.