Tunable Diode Laser Spectroscopy (TDLAS) technology is now widely used for natural gas leakage monitoring at field stations due to its excellent sensitivity, accuracy and anti-interference properties. In order to overcome the limitation that a single TDLAS laser telemetry instrument cannot obtain the influence range of leakage gas diffusion, an intelligent monitoring method based on the collaboration of multiple TDLAS telemetry instruments is proposed in this paper. By scanning the leaked gas masses in different oblique planes, the outer contour equations of gas leakage in different oblique planes according to the Brianchon's theorem are obtained. The three-dimensional spatial leakage impact area of natural gas is reconstructed to carry out monitoring and early warning in real time.