In this paper, an improved algorithm based on Housner spectral intensity is proposed. The upper and lower limit time range of the equation is adjusted to 0.1s similar to 10.1s. At the same time, the equation of spectral intensity value is divided into six categories. The spectral intensity value is calculated according to the range of lgSI(0.2) calculated. Finally, the ordinary Kriging interpolation method is used to draw the spectral intensity contour map. The improved method proposed in this paper establishes a continuous function relationship between the acceleration time-history integral of ground motion and the spectral intensity. Through the comparison and verification of two earthquakes, the spectral intensity contour map obtained by the improved algorithm is consistent with the overall change trend of the macroscopic intensity map, and has a good corresponding relationship. It has certain reliability and accuracy, and can provide scientific data support for post-disaster emergency rescue and decision deployment.