This paper presents a theoretical analysis on the percussion counter-force of the breaker as well as the stress on its main boom. An experimental study is made of the strength of the main boom with a rubber buffer being installed on the breaker connection seat. 本文就碎石器的冲击反力、主臂应力进行了理论分析,并对在碎石器连接座上设有橡胶缓冲装置的碎石机主臂强度进行了测试研究。