A solar cell and preparation method thereof. The solar cell includes a silicon substrate having first or second polarity, where the substrate includes first and second sides opposite to each other; a first passivation structure on first side of the substrate, where a portion of first structure farthest from the substrate has first polarity and a position where first structure is located is first electrode region; a second passivation structure on a side of first structure away from the substrate and in at least second electrode region, where a portion of second structure farthest from the substrate has second polarity and second structure has a process temperature lower than first structure; and a first electrode in first electrode region on a side of second structure away from the substrate, and a second electrode in second electrode region on a side of second structure away from the substrate.