Efficient and safe transposon integration system and use thereof

Provided is nucleic acid construct and a use thereof. The nucleic acid construct comprises the following elements in turn: a transposon 5'-terminal repeat sequence, a polyclonal insertion site, a polyA tail signal sequence, a transposon 3'-terminal repeat sequence, a transposase gene coding sequence and a promoter controlling the expression of the transposase, wherein the polyclonal insertion site is used for operably inserting a foreign gene coding sequence and the optional promoter is used for controlling the expression of the foreign gene; the polyA tail signal sequence has a polyA tail signal function in both the forward and reverse directions; and the direction of the expression cassette of the transposase is opposite to the direction of the expression cassette of the foreign gene. The nucleic acid construct can be used to mediate the expression of the foreign gene in a host cell.