Gully erosion is a dominant process causing severe soil loss and soil degradation in the Dry-Hot Valley region of southwestern China. Little attention has been paid to the spatiotemporal variations of the morphological characteristics of gullies. The aims of the present study were to explore gully morphological characteristics and its soil mechanical properties. In our study, we identify the main types of gullies according to their activity and the characteristics of their impact factors in the study area. Results showed that 1) three different active gully types could be classified: active, semi-active and stable; 2) the morphological characteristics of different active gullies were significantly different; 3) the soil shear strength under different parts of gullies varies with different active degrees of gullies; and 4) the gully head-cut height, gully wall-slope and its bed-gradient ratio were the most important indicators for reflecting gully morphology, which was affected by soil mechanical properties in it. It is the premise and foundation of further study on gully erosion to carry out the study of a gully’s morphological characteristics. These findings improve the understanding of a gully’s morphological characteristics and its soil mechanical properties in the Dry-Hot Valley region.