Visual object tracking is always a fundamental block in the field of computer vision.The task scenarios of object tracking technology include single object tracking and multi-object tracking.In this work,we contribute the comprehensive and most recent review on the problem of single object tracking.First,a thorough review on these algorithms in recent decades is shown.Then,existing approaches,which have been proposed to tackle this problem of single object tracking,are divided into different categories,and each category is discussed in detail for the principles,representative models,advances and drawbacks.What's more,this work also provides a discussion about the difficulties and some interesting directions which could possibly become a potential research hotspot in the future.This work can be an effective reference for researchers in this field to quickly learn about the technology of single object tracking.