【Objective】To grasp the deformation characteristics of Jiangxi red clay under the action of straight shear plus unloading and the law of energy dissipation. 【Methods】Direct shear tests under shear loading and unloading conditions were carried out on Jiangxi red clay, and its strength-deformation characteristics and energy dissipation laws were analyzed. 【Results】The results show that: 1) Overall, the shear elastic displacement increases with the increase of normal stress. The shear elastic displacement at different unloading positions under the same unloading condition increases with the increase of unloading times. In the case of low normal stress, the slope of the red clay hysteresis curve with the increase of the number of unloading shows a nonlinear decay change, and the decay rate under the low normal stress condition is from slow to fast; 2) the red clay in the unloading and loading of the straight shear test process as a whole shows a shear shrinkage deformation, the shear unloading stage of the normal displacement increases, and then loading stage of the normal displacement first increases and then reduces the deformation, resulting in shear expansion deformation, and shear expansion is over when shear displacement reaches the value of unloading before. When the shear displacement reaches the value before unloading, the shear expansion ends. Shear unloading will increase the normal displacement of red clay, increase the shear shrinkage, unloading effect on the normal displacement with the increase of normal stress gradually decreases; 3) the same loading and unloading conditions of red clay shear strength with the increase of normal stress increases. The effect of loading and unloading on the shear strength of red clay is larger, and the effect of shear unloading under high normal stress is more obvious than that under low normal stress. 4) The dissipation energy of different unloading times under the same unloading condition increases with the increase of normal stress and the number of unloading and loading times, and the normal stress is between 100kPa and 300kPa, the dissipation energy of the unloading two conditions is larger than that of the unloading one condition. The dissipation energy of unloading twice is larger than that of unloading once at 100kPa to 300kPa, while that of unloading three times and four times is smaller than that of unloading twice, and that of unloading more times is larger than that of unloading once at 400kPa normal stress. 【Conclusion】: The dissipation energy and deformation of red clay under different loading and unloading conditions have certain regularity.