To calculate the thermal characteristics of the rectangle liquid droplet radiator more accurately, a novel method, which estimated the characteristics of each droplet, was introduced. The shape factors of two and three droplets were theoretically deduced and verified by the Monte Carlo method. It was found that the shape factor of two droplets depends only on the ratio of the distance between the two droplets to the radii of droplets. According to this characteristic, the shape factor of two droplets was calculated and fitted to be a formula, which makes it convenient to calculate the shape factor in the following analysis. Based on the superposition rule of the shape factor, a shape factor matrix was introduced to calculate the effect of surrounding droplets when analyzing the heat transfer of the droplet sheet. The temperature distribution of the droplet sheet was calculated based on the shape factor matrix, which obtained using the combination of theoretical method and Monte Carlo method. The results showed that the temperature difference among the droplets on a same width-thickness plane was negligible. Therefore, a simplified model was developed based on this characteristic. The discrepancies of the temperature distributions obtained by the original model and the simplified model were found to be less than 0.35%, which demonstrates the feasibility of the simplified model to analyze the thermal characteristics of the rectangle droplet radiator. By further analyzing the heat transfer characteristics of the droplet sheet, proposals were made for design of the rectangle liquid droplet radiators. (C) 2018 Elsevier Ltd. All rights reserved.