Abstract: Data analysis for thermal pulse method (TPM) applied to space charge distribution measurement of polymer dielectric film involves the Fredholm integral equation of the first kind. Complying with traditional way to extract space charge distribution by differentiating electric field may aggravate the calculation error arisen from the ill condition of inverse problem solution. A novel way to directly calculate space charge distribution by TPM was proposed in this paper. Combined with the one-dimension heat conduction equation, thermal response current integral equation with the direct solution target of space charge distribution was deduced. Based on the two numerical algorithms, Tikhonov regularization and scale transformation method (ST), several numerical examples were utilized to analyze the impact of the thermal response current with various signal-to-noise ratios (SNR) on retrieved space charge distribution results. The merits and demerits of the two applied numerical algorithms for calculating space charge profiles were also discussed. The results demonstrate that the proposed way, according to several examples of the two algorithms, can overcome the ill condition of the Fredholm integral equation of the first kind and improve the calculation accuracy of space charge distribution with very few unexpected oscillations and low sensitive to SNR of the original current.