A nuclear reactor fuel element failure analysis method based on a meshless method comprises the following steps of: 1, establishing a particle geometric model, and initializing particle parameters; 2, updating adjacent point particles, and calculating a weighting function and particle number density; 3, calculating energy conservation, and updating enthalpy values, temperatures and phase states of particles; 4, performing eutectic reaction calculation, updating the content and the physical property of particles, and updating the enthalpy value, the temperature and the phase state of the particles; 6, calculating the gravity, viscosity and surface tension of the fluid, and estimating the speed and position of fluid particles; 7, calculating solid motion, and updating the speed and position of solid particles; 8, correcting viscosity, and updating the speed and the position of fluid particles; 9, updating the load of the fluid on the solid; and 10, outputting data. According to the method, all phenomena in a nuclear reactor fuel element failure process are considered; on the basis of a meshless method, interface changes can be accurately captured, and compared with a grid method, the problem of grid distortion in large deformation is avoided; and the algorithm process is easy to realize large-scale parallel computing.