The structure and thermal management of many-heat focus resonator is more flexible than that of single heat focus resonator. Whereas, the stability of many- thermal focus resonator is affected by more factors, such as the arranging of laser head, which need optimizing design. To get stability output, the single focus double rod resonator, the double focus 3 rod symmetrical resonator and the double focus 3 rod laser with unsymmetrical cavity are analyzed and compared. With the theoretic results, by mounting three laser heads with two thermal focus into a flat-flat symmetrical thermally-near-unstable resonator, a continuous-wave power stabilized output of 1125 W at 1064 nm is obtained with a optical-optical conversion efficiency of 32% and a beam quality of 15 mm·mrad under the pumping power of 3480 W.