Abstract: Objective Laser concentration sensors are widely used for measuring the concentration of welding fume. However, this type of sensor cannot directly measure actual concentration of welding fume. It needs to be calibrated before testing to realize on-line detection of welding smoke concentration. Methods Based on filter membrane weighing method and laser scattering method, a calibration device is redesigned and assembled. The calibration coefficients of welding fume for four popular welding consumables are measured with this device. Results The results show that sensor calibration coefficients K of welding fume formed by JQMG70S-6 solid wire, JQ-CE71T-1 flux-cored wire, E5015 basic electrode and E4303 acid electrode are 60.4, 19.7, 20.6 and 19.6, respectively. Conclusion Error analysis of experimental results shows that precision and accuracy of measurement results of the calibration device can satisfy measurement requirements with high accuracy.