<p>The equal thickness profiling is an essential machining process in continuous on-line processing for bearing shells, where alloy coating of bimetallic sheet is processed to equal thickness based on the profile of the steel backing. Existing profile processing schemes have limitations as complicated structures, high cost or low efficiency, which are not suitable for mass processing in production lines. This paper proposes an effective equal thickness profiling approach presented as ‘synchronous partitioning measuring-milling’ (SPMM) for bimetallic sheets based on on-line active visual measurement, where an efficient image segmentation method is presented as well. Area to be processed partitioned into slices, the bimetallic sheets is paralleled measured and processed synchronously based on the active visual measuring results. The experimental results show that the proposed synchronous partitioning measuring-milling approach for bimetallic sheets can satisfy the accuracy and efficiency of continuous online processing for bearing shells, as well as good stability and robustness.</p>