The utility model discloses a multi -functional hydrophobic board, including the water proof main part to reach a plurality of cavity bulges with water proof main part integrated into one piece, the water proof main part is reelable cranked rectangle structure, and what the bulge was even regular attaches to arbitrary one side of water proof main part, the bulge includes blind end and open end, and the blind end is located evagination one side of bulge to be equipped with horizontally closed bottom, the open end is located the other end of bulge, and the opening of open end and the smooth connection of water proof main part. To the hydrophobic board of current plastics material, there have the vertical intensity to be not enough, arouses the deformation in the construction, and then influence construction quality's problem, through setting up the support column, has increased fore -and -aft holding power, simultaneously, add the compact part through set up the edge at marginal portionto and the interval set up in the middle of the vertical and horizontal compact part that adds, make hydrophobic construction, have stronger adaptability, improved efficiency of construction and construction quality.