The invention discloses a construction method for assisting an open caisson to sink without drainage by using a rotating drilling machine, which comprises the following steps of: S1, arranging at least one trolley on a track at the top of each longitudinal open caisson compartment, and hoisting the rotating drilling machine to a transverse moving trolley of the trolley; S2, carrying the rotating drilling machine by the trolley to move to a rack platform on the inner wall of a first compartment, mounting a drill rod to the rotating drilling machine, and drilling by using the rotating drilling machine in the first compartment until a preset drilling depth is reached; S3, moving the rotating drilling machine to the rack platform of the first compartment, releasing the connection with the drill rod and moving to a second compartment, repeating step S2, completing the drilling of the second compartment, repeating and finishing the drilling of each single compartment; S4, disassembling all the equipment after the open caisson sinks to a preset position. According to the construction method, when the soil is broken and the mud is sucked efficiently under a non-sandy soil condition, the compartment can be quickly rotated, so that the purposes of enlarging the application range and improving the working efficiency are achieved.