With increasing attention on insulating liquids for green and environmentally friendly power equipment, modified natural esters represent a type of renewable energy featuring excellent insulating properties and significant application potential as novel liquid insulating media. In this paper, focusing on the pyrolysis gas production characteristics of lauric acid modified ester, the mixed system models of three lauric acid modified ester were constructed. Then, based on ReaxFF reaction force field, the reaction molecular dynamics simulation was carried out to analyze the pyrolysis process of lauric acid modified ester molecules under electric heating and the distribution of gas products from the molecular point of view. The results show that the ester group is the weak link of the lauric acid modified ester, which is the first to crack to produce CO2 under the action of high temperature. The cracking rates of the three lauric acid-modified esters followed the trend C13H26O2 < C14H28O2 < C20H40O2. CO2 content is highest during low-temperature overheating, while C2H4 levels increase during medium-temperature overheating, and H2 content rises during high-temperature overheating. Furthermore, CO and C2H2 are identified as the characteristic products of medium- and high-temperature overheating, respectively. These results offer theoretical insights into the pyrolysis gas production characteristics of lauric acid-modified esters.