Abstract: The blade with tips can be equivalent to the model of mass with springs in this paper. It is achieved for the blade with tips to be damping by means of the multiple motions of impact and friction between the blades with tips, so in the paper, the friction between blades with tips can be equivalent to the spring and damping model with symmetry gap. Sgn contact model is used, thus the paper gets the dynamical equation of the system, and solves the equation by Runge-Kutta numerical method. The paper mainly discusses how the parameters such as gap of tips, stiffness ratio, contact angle, friction coefficient make impact on damping effect. The result shows that the parameters make an important impact on vibration energy, selecting parameter is subjected to span of rotate speed. The multiple motions of impact and friction between the blades with tips is hard piecewise linear vibration which is actually nonlinear, so the paper also makes certain research on the nonlinear characteristic of the system by means of Poincaré graph and frequency spectrum etc.