In order to achieve high power, high brightness lasers, a TEM00-mode dynamic stable resonator with two Nd:YAG rods is constructed. The thermal induced birefringence is compensated by two identically pumped rods. The laser output 61W is achieved in cw mode under lamp pumped regime. The influence of the cavity parameters on the laser output properties is investigated using the equivalent thermal lens method. It turns out that the distance of the output coupler and the high reflectivity mirror from the laser rods play different roles on the laser properties.