The traditional method for calculating laser induced damage threshold (LIDT) value of thin films is based on qualitative or semi-quantitative empirical formulas, the results obtained are of low accuracy and credibility. A new method for accurately calculating LIDT values of thin films is presented in this paper, when a thin film is subjected to intense laser irradiation, the distribution models of internal electric field-absorption-temperature field are constructed respectively. In general, when the corresponding temperature value at a certain time and a certain depth is the maximum value in the temperature field distribution of the thin film, the incident laser energy is the damage energy threshold of the thin film at this time, and the depth is the location where the thin film is most prone to damage. Therefore, an expression of the relationship between the damage energy threshold and the maximum temperature can be established, which can be used to combine to the relation expressions of critical electron density with temperature maximum and damage energy threshold respectively, the LIDT values of the thin films can be solved simultaneously. In order to verify the reliability of the method, the LIDT values of single-layer titanium dioxide, silicon dioxide and diamond-like carbon (DLC) thin films were calculated respectively, their experimental values are obtained at the same time, and each film’s theoretical value was compared with the experimental value several times The results show that their theoretical values and experimental values are consistent, indicating that this new method for calculating LIDT of thin film is feasible, and it not only enriches and develops the traditional theoretical calculation methods, but also provides a new judgment basis for evaluating the resistance to laser damage of thin films.