The present utility model discloses a utility knife with dual blades, comprising a housing having an opening at both ends, a blade carrier which is mounted and is movable within the housing, a movement assembly connected to the blade carrier for driving the blade carrier to respectively move in a direction towards both ends of the housing, wherein it further comprises a stop member. The blade carrier is provided with an abutment portion thereon, and the stop member has a stop portion being able to change its position with respect to the abutment portion, so that the blade carrier can move in a single direction so as to prevent the blade carrier from accidentally sliding and pushing the blade out to injure a user.