This paper proposes a new kind of racetrack-shaped high-temperature superconducting (HTS) magnet for a stator fieldexcitation HTS machine, for the purpose of implementing stationary seal at the cooling Dewar. The key is to introduce a vacuum sandwich-structure into the proposed racetrack-shaped Dewars so that the operation temperature of field-excitation windings can be regulated at 63 K. The method of reducing pressure by vacuuming is applied accordingly to decrease the temperature of cryogenic liquid nitrogen to ensure the cooling effect. The test results show that all the fabricated racetrack HTS magnets can operate at HTS state when the excitation current reaches 40 A. Hence, the proposed racetrack HTS magnet is experimentally verified.