The invention discloses an adjustable supporting pier for boat, which comprises the following parts: lower base, upper sliding body, lever, lever shaft, starting device, safety device, limit hook and baffle, wherein two sides of lower base top are inclined-planes; respective inclined-plane of two upper sliding bodies connects two inclined-planes of lower base top; two levers are set in the lower base through lever shaft connecting two sides of lower base, which lie between two inside plates of lower base; the long shaft of lever can rotate to the bottom of lower base; two end shafts of starting shaft in the starting device pierces the bottom of lower base, whose two side shafts exposes out of case plate of lower base to push two side shafts to start the wedge through opening sliding along the floor; the adjustable support pier presses left and right slider with short shaft of lever entering the groove of upper sliding body, which pushes the lever rotate until the bottom of lower base; two side inclined surfaces support the bottom of lever, which fixes two upper sliding bodies to close the safety device. |