An analytical power model based on the rate equations of a high-power Yb-doped double-clad fiber laser is presented. Although it considers combiner and splices losses for the first time, the maximum and mean relative errors are less than 2.2% and 3.04% when compared with numerical and experimental results, respectively. Furthermore, an analytical temperature model based on thermal conduction equation has been reported. For the first time, the radial-dependent distribution of the heat density generated inside the fiber core is considered. Radial and longitudinal 3D distributions for temperature are presented. The results show a big difference (can reach 25%) when compared with conventional models, which consider a uniform radial distribution for heat density. In contrast, the mean relative error related to our model is less than 4.7% when compared with experimental results, whereas it reaches 9.3% in the conventional one.