A blade unit for a brush cutter of the present invention comprises: a housing which comprises a first housing member, a second housing member, and a pull-in/take-out unit which is distanced from the ends of the first housing member and the second housing member by a certain distance； blades which comprise: an eccentric support unit which is rotatably supported by a hinge pin in the direction of a circumference to be distanced from the center of the housing by a certain distance, to be taken out to the pull-in/take-out unit, to be combined with the hinge pin, and to have an eccentric outer circumferential surface； and cutting units which are extended from the eccentric support unit to cut grass； and an elastic support unit which is installed in the housing to come in contact with the eccentric support unit of each of the blades, and to give an elastic bias to each of the cutting units in the direction of being taken out from the pull-in/take-out unit. The present invention aims to provide a blade unit for a brush cutter, which can provide uniform elasticity to a plurality of blades and prevent cutting ability from being lowered by coming in contact with grass while cutting the grass.본 발명의 예초기 컷팅날 유닛은 제1하우징부재와 제2하우징부재로 이루어지며, 제1,2하우징부재의 단부가 소정간격 이격되는 인입인출부를 가지는 하우징과, 상기 하우징의 중심으로부터 소정간격 이격되도록 원주방향으로 힌지핀에 의해 회동가능하게 지지되어 인입인출부로 인출되는 것으로, 상기 힌지핀과 결합되며 편심된 외주면을 가지는 편심지지부와, 상기 편심지지부로부터 연장되어 풀을 베기 위한 커팅부를 가지는 커팅날들과, 상기 하우징에 설치되어 상기 각 컷팅날의 편심지지부에 접촉되어 각 컷팅부들이 상기 인입인출부로부터 동시에 인출되는 방향으로 탄성바이어스 시키는 탄성지지유닛을 구비한다.
