[Objective] The interactive relationship between urban compactness and land use efficiency was explored, in order to provide a basis for promoting new urbanization and high-quality sustainable development in the region. [Methods] The index system was established based on the model of coupling urban compactness and land use efficiency, and the spatial and temporal characteristics of the relationship between them in Guangxi Zhuang Autonomous Region from 2003 to 2018 were analyzed by using the weighted summation method and the coupling coordination degree model. [Results] ① The urban compactness of Guangxi Zhuang Autonomous Region from 2003 to 2018 showed a fluctuated upward trend, and the compactness index increased from 0.301 to 0.433. The high compactness cities were mainly distributed in central and Northern Guangxi, the cities of low compactness were concentrated in Northwest Guangxi and Southeast Guangxi on both sides, and the cities of medium compactness were ringed around the cities of high compactness. ② The land use efficiency of cities in Guangxi had experienced the gradient improvement process of “steady optimization-accelerated growth”, and the scores had risen from 0.363 to 0.574. The land use efficiency showed the spatial pattern of high in the north and south, and low in the east and west. ③ The coordination degree of coupling between urban compactness and land use efficiency in Guangxi area increased from 0.408 to 0.504 at a low speed, the coordination type transitions from barely coordinated to primary coordination. Each city experienced the evolution process of “on the verge of disorder—barely coordinated—primary coordination”. In general, the coordination type showed the pattern of “point surface—cluster—linear belt”. [Conclusion] The mutual promotion role of urban compactness and land use efficiency in Guangxi area is weak, and their coordination relationship is not close. Promoting the coordinated development of them plays an important role in solving the negative problems in the process of urbanization.