In this paper, a comprehensive analysis and comparison is fulfilled between the four classical intensity theories, Mohr´s intensity and a new balance particle intensity theories. A comparative study is developed between the test results of pulling or pressing in single direction and double directions. It is shown that the new balance particle intensity theory is more coincident with the test results than other five intensity theory. Especially, the intensity formula of pulling (bending)shear (torsion) deduced from the particle balance theory can easy explain the phenomena that pulling makes the destructions easy and suppression makes the destruction hard to achieve. This phenomenon cannot be well explained by the four classical intensity theories and Mohr’s intensity theory. The particle balance intensity theory clarifies the misunderstanding that if the equivalent stress is zero, the third and fourth intensity theory regard that the beam under three or fourdirections cannot be destroyed whatever the force is. The balance particle intensity theory figures out a contrary conclusion with the third intensity theory and fourth intensity theory.