R-continuous bits matching is the most fundamental and common-used rule in AIS, which is used to measure the similarity between detectors and strings to be detected. Usually the time complexity is proportional to the size of detectors used (denoted as NR). To improve the runtime detecting efficiency, a rapid r-continuous bits matching algorithm is presented in this paper. Our algorithm first produces location vectors before handling real detection. Location vectors record the position information of all possible r-bits patterns extracted from the detector set. When detecting a string, our algorithm just queries location vectors and no need to access the detectors in use. Time complexity of our algorithm in run-time detection period is O(l-r+1) which is a dramatically progress compared to the original time complexity O(NR.(l-r+1)). Furthermore, this time complexity is irrelevant to the size of detector set used. This valuable characteristic makes it especially suitable for large-scale immunocomputing where NR may be very large.