Weld quality control is of great importance in tailored blank laser welding for the purpose of making products at a high quality and high productivity. In general, the controllable parameters are only indirect data on features of the final weld to be made. In this paper, direct correlation between weld concavity and weld process parameters including weld gap and torch offset are discussed based on theoretical analyses and experiments. A direct control model is established according to the analysis of reasons causing weld concavity. This model will improve the quality of laser welding process by accurately controlling the weld geometry in real time.