The availability and accuracy of molecular force fields limit their application scope. In this work, a first principle and all-atom force field for 1,3,3-trinitroazetidine (TNAZ) was developed based on the TEAM method. The valence parameters and atomic partial charges were derived by fitting to ab initio data. The van der Waals (VDW) parameters were taken from the literature and optimized using experimental densities and vaporization enthalpies of liquids. In order to validate the force field, the properties of TNAZ in gas, solid and liquid states were calculated. It has been shown that the force field is highly accurate in predicting the above properties, which include molecular structures, vibration frequencies, liquid densities, vaporization enthalpies, crystal structures, and lattice energies. The isobaric and isotherm curves of the condensed phases were calculated. The isobaric curves can be partitioned into three regions. The volume of crystalline TNAZ at 300 K is about 13% smaller than that at 400 K, which is consistent with the experimental observation. The volume of crystalline TNAZ is reduced by about 28% when the system is compressed under 10 GPa pressure and 300 K, which is consistent with other theoretical predictions.