In SAW panel welding, which involves single-pass welding on the front and back sides of a steel plate, careful selection of welding parameters is crucial to achieve sufficient bead penetration and a smooth surface, preventing structural issues. To optimize these parameters, several studies have been conducted using statistical approaches. This study focus on investigating the impact of welding variables, such as welding current, voltage and speed, especially on weld reinforcement during bead-on-plate welding with tandem SAW. A total of 32 experiments were carried out based on a response surface methodology and the surface shape of the bead was recorded using a laser displacement sensor. The results showed that weld reinforcement was affected by leading electrode current, voltage and trailing electrode voltage. However, it was found that the trailing electrode current have no significant effect on the height of the weld bead. From the results, regression model was developed, leading to the establishment of an optimal range of welding parameters for achieving the desired weld quality.