A dental floss holder capable of controlling tension, the dental floss holder comprising: a body in which a head, to which a part for directly removing foreign matters of teeth from a dental floss is suspended, is provided at a front end thereof, a winding hole is through-formed in the middle thereof, and a locking pole which can be elastically deformed is formed around the winding hole; and a winding wheel which is inserted to the winding hole of the body to be rotatably provided, fixed with a part of the locking pole being suspended thereto, and pulls the dental floss to maintain predetermined tension while rotating together when a part of the dental floss is suspended, wherein the locking pole is formed in a cantilevered shape which is elastically deformable based on one end thereof, locking protrusions are formed at the front end thereof to protrude in a longitudinal direction of the locking pole, locking grooves are grooved at predetermined intervals at a cylindrical insertion portion of the winding wheel along a trajectory which comes in contact with the locking protrusions while the winding wheel is rotated so that the locking protrusions are inserted to the locking grooves to fix the winding wheel, wherein the locking grooves are formed on the outer peripheral surface of the cylindrical insertion portion of the winding wheel, the winding wheel includes a rotary grip to be gripped by a user; the cylindrical insertion portion which is formed on one surface of the rotary grip to protrude in a cylindrical shape, inserted to the winding hole, and has a fixing slit formed in a longitudinal direction so that a part of the dental floss is suspended in the middle thereof; and fixing protrusions which are formed to protrude from one end of the cylindrical insertion portion to be suspended to a fixing guide formed to protrude around the winding hole, thereby preventing the winding wheel from being arbitrarily separated, and the fixing protrusions are formed in a cross shape based on an insertion portion of the fixing slit and provided at a pair of insertion portions facing each other and divided by the fixing slit. a body in which a head, to which a part for directly removing foreign matters of teeth from a dental floss is suspended, is provided at a front end thereof, a winding hole is through-formed in the middle thereof, and a locking pole which can be elastically deformed is formed around the winding hole; and a winding wheel which is inserted to the winding hole of the body to be rotatably provided, fixed with a part of the locking pole being suspended thereto, and pulls the dental floss to maintain predetermined tension while rotating together when a part of the dental floss is suspended, wherein the locking pole is formed in a cantilevered shape which is elastically deformable based on one end thereof, locking protrusions are formed at the front end thereof to protrude in a longitudinal direction of the locking pole, locking grooves are grooved at predetermined intervals at a cylindrical insertion portion of the winding wheel along a trajectory which comes in contact with the locking protrusions while the winding wheel is rotated so that the locking protrusions are inserted to the locking grooves to fix the winding wheel, wherein the locking grooves are formed on the outer peripheral surface of the cylindrical insertion portion of the winding wheel, the winding wheel includes a rotary grip to be gripped by a user; the cylindrical insertion portion which is formed on one surface of the rotary grip to protrude in a cylindrical shape, inserted to the winding hole, and has a fixing slit formed in a longitudinal direction so that a part of the dental floss is suspended in the middle thereof; and fixing protrusions which are formed to protrude from one end of the cylindrical insertion portion to be suspended to a fixing guide formed to protrude around the winding hole, thereby preventing the winding wheel from being arbitrarily separated, and the fixing protrusions are formed in a cross shape based on an insertion portion of the fixing slit and provided at a pair of insertion portions facing each other and divided by the fixing slit.