Abstract: Based on tunable diode laser absorption spectroscopy technique, two-dimensional temperature field in combustion was reconstructed using modified adaptive algebraic reconstruction technique (ART). Aimed at achieving an optimal reconstruction result with limited number of beams, the influence of the beam parameters and grid number on temperature field reconstruction was investigated. A virtual beam method with virtual beams added adjacent two beams and an increased number of grids was developed to describe the reconstructed temperature field in detail when the number of beams was limited. The simulation results indicate that the normalized mean absolute error is low when the ratio of beam spacing to the grid spacing was between 0.6 and 1. Compared with other methods, the normalized mean absolute error is significantly reduced using the virtual beam method.