The speed of general connected component detection algorithms was slow, and most of these algorithms needed more than one scanning. A connected component detection algorithm was presented based on Breadth First Search(BFS) with the First In First Out (FIFO) queue. The algorithm was a non-recursive algorithm, the connected component could be detected by one scanning, and the storage space and running time could be reduced. We used a particular scanning template to process each pixel, avoiding more than one scanning. The multi-core parallel processing was used to accelerate the algorithm, and it realized the truly parallel computing. With the connected regions ordered from top-left to bottom-right, a reverse merging method was proposed to simplify the complexity of region merging. The experimental results show that the detection rate has been greatly improved.