The invention relates to a fully-sealed follow-up sealed flatcar for an engineering drilling machine. The fully-sealed follow-up sealed flatcar comprises a chassis, wherein a first half-sealed flatcar and a second half-sealed flatcar which move relative to the center of the chassis in an opened and closed translational motion manner are embedded into the chassis; the first half-sealed flatcar and the second half-sealed flatcar both consist of sealing beams, middle sealed platforms and end part sealed platforms in sequence from the center to outside of the drilling machine; the sealing beam is hinged to the middle sealed platforms; the middle sealed platforms are hinged to the end part sealed platforms; the end part sealed platforms are hinged to the chassis; turnover plates are arranged above the middle sealed platforms and above the end part sealed platforms; the right ends of the turnover plates are hinged to the end part sealed platforms; the left ends of the turnover plates are in lap joint with the middle sealed platforms; a push device which is horizontally arranged is connected between the left and right sides of the sealing beams and the chassis. By adopting the fully-sealed follow-up sealed flatcar, security of operators and facilities on the sealed flatcar can be effectively ensured, and meanwhile, the minimum working space on the chassis of the engineering drilling machine is also achieved.