Abstract: In image processing,the registering system of Rotary Screen Printing Machine(RSPM) needs to meet the demand of real-time inspection.This paper presents a fast matching algorithm based on pattern inspection system research of RSPM,its goal is to obtain the position vector of off-pattern-image,builds the foundation for the later closed-loop control.The algorithm combines the point pattern matching algorithm and the block-matching algorithm.Block matching strategy reduces the data computing and improves the operation speed,the simulation results show that it outperforms traditional matching algorithms of grey level based full search strategy,and it is a practical and suitable matching algorithm,it can not only achieve high accuracy,but also improve computing speed through the block matching strategy.The online inspection of RSPM can be realized.