In recent years, with the rapid development of Advanced Driver Assistance Systems (ADAS), the demand for the precise and efficient surround view stitching system has significantly increased. Traditional stitching methods perform well in small single-unit vehicles with stable camera poses. However, the stitching quality sharply degrades when applied to large tractor-trailers due to the continuous pose changes caused by the non-rigid connection between the tractor and trailer. In detail, first, the extended length of tractor-trailers results in low overlap between cameras, making feature extraction and matching challenging. Additionally, the stitched images often appear irregular, detracting from visual quality. Besides, even if static stitching looks natural, it causes jitter in dynamic scenarios due to random feature extraction. In this paper, we propose an unsupervised deep stitching method for tractor-trailer surround view system. We introduce a feature extraction module for tractor-trailer scenarios (FMT) to enhance feature extraction in low-overlap situations. Besides, we design a spatio-temporally consistent control point constraint strategy (STCC) to achieve spatial shape preservation and temporal smoothing effects, resulting in visually consistent and stable stitched sequences. Experimental results from both public and real dataset show that our method efficiently completes tractor-trailer surround view stitching, producing well-aligned and natural panoramic images compared to previous methods.