A support assembly for supporting photovoltaic panels includes a plurality of support units connected one by one. Each of the plurality of support units includes a support beam, a pair of standing posts, a strengthening bar and at least one horizontal beam. The pair of standing posts, the strengthening bar and the at least one horizontal beam are pivotably mounted on the support beam via connecting members. When used, the strengthening bar rotates relative to the support beam and collectively constitutes a triangle with the support beam and one of the pair of standing posts to avoid distortion. When packaged, the pair of standing posts and the strengthening bar rotate relative to the support beam to be received in the receiving groove respectively, and the at least one horizontal beam rotates relative to and is disposed in parallel to the support beam.