In order to improve the walking pattern and terrain adaptability of the close-chain legged system, an octopod platform with a reconfigurable trunk is proposed. To overcome the limitations of the singular trajectory of the close-chain leg mechanism, we develop an 8R reconfigurable trunk with multiple motion branches that can endow the platform with a range of gaits. These gaits can be classified into two modes: wide and narrow. The kinematics of reconfigurable trunk is analyzed and trunk configurations with different motion patterns are developed. In addition, each gait is matched with a corresponding control and switching strategy. In terms of climbing capabilities, a probabilistic model is developed to assess the proficiency to climb obstacles based on the pitch angle of the close-chain leg mechanism. In terms of stability during slope walking, the stability analysis of the platform on longitudinal and side slopes is developed. Our research suggests that the use of a reconfigurable trunk enhances the various gaits and improves the terrain adaptation of close-chain legged platforms.