Abstract: A solar cell and a manufacturing method thereof, and a photovoltaic system. The solar cell includes: a substrate layer including a first surface and a second surface arranged oppositely along a thickness direction thereof; a tunnel oxide layer, a first doped polysilicon layer, and a first passivation layer sequentially arranged on the first surface of the substrate layer in a direction gradually away from the substrate layer; and a first finger electrode layer, at least one of the first fingers being arranged in first connection holes, bottoms of the first connection holes being located in the first doped polysilicon layer, and the first fingers passing through the first connection holes corresponding thereto to be electrically connected to the first doped polysilicon layer; and in the first direction, widths of the first connection holes being all less than widths of the first fingers corresponding to the first connection holes.