Based on the laser absorption spectroscopy technique and algebraic tomography reconstruction, two-dimensional temperature distribution is reconstructed by using an irregular beam array. The grid weight factor which represents the number of lines across the grid is put forward and used to evaluate the distribution of the line. An improvement of reconstruction is obtained by optimal line distribution. The reconstructed quality with error of less than 15% compares with the non-optimal beam and parallel beam distribution reconstructed results. The reconstructed quality increases with number of emitters increasing. Time division multiplexing technology is adopted to scan two H2O absorption transitions (7205.25 cm -1 and 7416.05 cm-1) simultaneously at 1 kHz repetition rate. Additionally, the numerical results agree well with the experimental results.